Messy Interactions

by Tsunogami

Rating: mature
Tags: Romance, Fluttershy, Sex, Princess Celestia, Slice of Life, Sweetie Belle, My Little Pony: Friendship is Magic, Princess Cadance, Rarity
Length: 26041

How diaper play can bring close ponies even closer, especially when they are sisters.

A number of my readers have already read the first chapter of this story as it first appeared as chapter 7 of An End to Ignorance. However I have decided to make it a stand alone story. Though both occur in the same "universe".

Primary concept is: Rarity/Sweetie Belle incest with a bit of foalcon in the flashback scenes. plus messy diaper play among other ponies in later chapters.

This story contains heavy diaper usage, scat play, and scat sex. Also will include shiny clothing fetish themes. If you don't like it then go write your own stories.

Published 2016-01-07 07:10:02 UTC
Last updated 2016-09-07 03:02:35 UTC

Ch 1: Sibling Interactions, or, Love At Home

Being a lazy pony was something to which Rarity would never admit. First of all, it was not true, and second of all what she was doing this afternoon was not, strictly speaking, being lazy. In her line of work she could never afford to be lazy. Lazy had not allowed her to expand her fashion empire into Equestria’s capitol city and now into the Chrystal Empire. And lazy had not gotten her the bits necessary to purchase this penthouse apartment both overlooking the Celestial Valley and within easy walking distance of the gates of Canterlot Castle itself. To be honest, what she made selling dresses to Canterlot nobility had not been enough on its own to afford a place such as this, but with what she made at her other “career”-so to speak- it had been sufficient. That's not to say she no longer considered Ponyville as her home, quite to the contrary, this penthouse was simply where she came to stay when business matters kept her in the big city for more than a day at a time. Her connections to that town ran far too deep for her to ever consider abandoning it no matter where her business interests took her.

Besides, in terms of stress relief what she was doing now wasn’t so different from thoes wonderful spa treatments she tended to indulge in while living in Ponyville. Despite feeling a twinge of guilt at the vanity of it all Rarity couldn’t help but yet again stare at her reflection in the huge custom mirror taking up half the east wall of the sitting room. A room larger than most full bedrooms located off to the side of the penthouse’s master bedroom. The image staring back at her was one of a beautiful young adult mare with perfectly styled mane laying on her side on a plush red velvet sofa, eyes half closed in strange combination of sleepy desire. Had any other pony been lucky enough to see the same image as Rarity was now enjoying they would have immediately taken note that the mare in question was encased in a very tight, form-fitting black pvc catsuit.

Well, perhaps strictly speaking it wasn’t a true catsuit, it didn't cover any part of her head, nor did it cover her hooves, but it was close enough that she wasn’t about to bother with semantics. Many years ago when she had begun to experiment with wearing such garments she had bought a similar looking catsuit made out of latex. In the end the difficulty of maintenance, keeping it out of direct sunlight, having to use a special oil to keep it as shiny as possible, keeping it from being in contact with metallic objects, etc., etc., had keep Rarity from wanting to ever own anything like it again. Despite this dissatisfaction her desire for tight shiny things never truly went away and when pvc plastic began to be used as a clothing material she had jumped at the chance to try it out. The first ones she had tried were cheap and tore easily, but the artificial plastic material held so much more promise than the naturally occurring latex when it came to durability and ease of care. Undaunted, she had purchased more expensive versions made from thicker plastic and she had even begun to experiment with making her own. The process was not straightforward and required the purchase of new machinery for her design space but decent results were eventually had, much to her glee.

And now years later she was able to lay down and relax in a perfectly formed pvc outfit of her own design, made by her hoof picked employees. Rarity adored how its slick shiny surface reflected the light streaming through the large bay windows of the sitting room in fascinatingly different ways with only the slightest movement. She loved how it looked stretched tight over her firm thighs and toned legs. And she never got tired of how the slick interior of the catsuit felt as it slid over and pressed down on the soft fur of her entire body.

Under regular circumstances she would have found the catsuit alone to be enough for a good night of fun, and as a way of substantially increasing her monthly income. Not many mares who saw Rarity wear the thing at parties could resist paying a substantial sum to be the filly lucky enough to go home with her for the night and be licked and fucked in places they didn't even know had existed by one of the sexiest mares in Canterlot. However, this was not a day for parties- yet, which suited Rarity just fine, as the catsuit was not the only thing she was currently wearing. Any halfway observant pony would have noticed -after getting over the initial shock of seeing a pony as naturally good looking as Rarity wearing such a thing- how the catsuit bulged out around Rarity’s butt and crotch in a way not quite natural. One of the best things about a tight pvc catsuit not normally recognized even among the mares who commonly wore such things, was that if one were to wear a diaper underneath, the catsuit would hold that diaper very tight against the body of the mare in question. And of even greater importance, especially to a mare such as Rarity who is a bit obsessive about maintaining clean living spaces and personal appearance, the tight shiny plastic makes a perfectly moisture proof barrier between the diaper, -should the mare wearing it choose to use it for its intended purpose- and anything she may want to lay or sit on. Rarity loved being able to relieve herself of the concern that she might inadvertently stain anything she may try to sit on in her luxurious apartment simply by pulling one sexy garment over another.

All this was at the moment quite helpful, because Rarity was indeed currently wearing a very well used diaper under her catsuit, and without it she wouldn’t have dared lay around on one of her favorite sofas. Again she groaned as she turned herself over onto her back feeling the slimy mess in her extra dirty diaper squish between her exited pussy lips as it was pressed down into her crotch by the tight pvc surrounding the diaper. Every movement made her take a moment to steady her breathing and close her eyes as the new wave of pleasure passed over her. The true fact of the matter though, was that as amazing of a feeling as simply being in a diaper this wet and messy under a pvc catsuit was, it was only the second most dirty and erotic thing about her current situation.

The thing that really kept Rarity’s pulse racing and clit leaking was that the diaper she was wearing and the mess it contained were in fact not her own. Both had belonged, only an hour before, to the single hottest mare Rarity knew of. Her gorgeous, adoring, intelligent, cute, and sexy as fuck, little sister. Just thinking about Sweetie Belle’s warm slick brown shit- yes, shit, it felt even hotter in her mind saying it that way, coating her butt and being pressed into her pussy and up her vaginal canal with every rub to her crotch, was nearly enough to make her cum on the spot. Only years of practice at restraining herself in countless sessions of hot sex with thousands of mares kept her from exploding then and there. Rarity couldn’t help but run her hoof over the slick shiny surface of her pvc catsuit feeling her little sister’s mess squish around under the pressure. There simply was no better feeling a mare could give herself.

As to how her little sister had gotten into diapers, Rarity didn't think she would ever be quite sure, but she suspected it had something to do with Sweetie Belle sneaking into Rarity’s bedroom as a filly and discovering things she should not have. A few years back after a bed wetting “accident”, a claim that Rarity was never fully convinced of, Sweetie Belle had suggested to Rarity that perhaps she should wear a diaper and have a plastic sheet out on her bed until she was certain she would not have another accident. Rarity had of course agreed to this suggestion, all the while somewhat suspicious of her sister’s intent but never speaking up about it. After a bit of hunting around in the basement she found her own old plastic sheet from the time she had wet the bed as a filly, and that afternoon she had managed to procure for herself some surprisingly well made diapers from a company in Canterlot who specialized in diapers for fillies too old for the standard cloth baby diapers and too young to fit into any of the adult brands. She had given the package to an oddly excited filly who promptly took them back to her room without saying a word more on the subject for the rest of the day. The next morning Sweetie Belle had shown up in Rarity’s bedroom wearing one of the diapers which was quite thoroughly soaked apologizing for having another “accident”, while also asking if Rarity could help her keep this between the two of them and not involve their parents any further.

This same set of events played out again the following day with Sweetie Belle coming to Rarity’s bedroom and asking for Rarity to hide her wet diaper for her. And again the same thing the next day, and the next, and so on. Eventually Rarity simply stopped waiting for her sister’s arrival and instead went directly to her room to retrieve the wet diaper. This process continued even after one day around a month later, when Rarity arrived to find that Sweetie Belle had not simply wet her diaper but messed in it as well. At first Sweetie Belle had apologized for it though she declined to give any specific explanation as to why she had messed in the first pace. Though finding Rarity surprisingly not angry about it, Sweetie Belle had begun to mess her diapers every night thereafter.

*** 5 years ago ***

As it was a rather unusually warm night in early autumn causing Rarity to feel no particular desire to sleep under any sort of blanket, she simply preferred to lay on her side with only her natural fur as insulation. It was not due to any excess heat or the fact that it was still a good two hours before her regular bedtime that kept her eyes wide open this night, no, it was that this time she was finally going to do something about the fact that her little sister insisted not only on messing a diaper every night but having her change her out of it then secretly dispose of it every morning. Rarity refused to continue to be used as nothing more than a glorified babysitter, or worse, a nurse, by her little sister. No, if Sweetie Belle insisted on continuing in her hobby, then Rarity was determined to get something out of it for herself.

At first Rarity had agonized over deciding weather or not to go through with her plans. What of Sweetie Belle told their parents? What if Sweetie Belle was disgusted by the idea and distanced herself from Rarity from then on? What if…? No, these doubts were not logical. Sweetie Belle wouldn’t tell their parents because it would be every bit as embarrassing for her as for Rarity, and Rarity could only think of one reason why Sweetie Belle so consistently used her diapers every night and was so secretive about the process. Her little sister had become sexually aroused by the act. And if she was aroused by what she was doing now, then there was little reason to doubt she wouldn’t at least be intrigued by what Rarity had planned. The sound of Sweetie Belle’s door opening between her bedroom and the bathroom that was shared between their respective bedrooms reached Rarity’s ears through the closed door on her side of the bathroom. Without giving herself any more time to second guess her planned actions Rarity called out to her sister.

“Sweetie! I need to talk with you!” Rarity said with enough volume so that Sweetie Belle could not pretend she hadn’t heard, yet quiet enough that it was doubtful her parents, walking around downstairs would take any notice.

The sound of Sweetie Belle’s door opening ceased abruptly. After a few seconds of silence Rarity was pleased to hear the sound of hooves coming across the bathroom floor towards her room. Sure enough, the door from Rarity’s room to the bathroom opened slightly letting light spill across the wood floor of her dim bedroom. Sweetie Belle’s head soon appeared through the opening followed by the rest of her. For just a second Rarity paused as she admired the filly’s cute round butt surrounded by her thick disposable diaper.

“Um, what is it Rarity?” Asked the filly, her voice squeaking slightly.

“Come over here Sweetie,” Replied Rarity, patting her bed with a hoof. “We need to have a bit of a discussion.”

Looking appropriately nervous, Sweetie Belle did as requested, her thick diaper crinkling slightly as she came over and then hopped up next to Rarity on her bed.

“Now see,” Rarity began, trying her best to sound confidant yet not angry at the same time. She had no desire to make her sister afraid, yet she had to put on this air of confidence so that Sweetie Belle would know that there was no room for negotiation.

“As you know, I do not mind that you wear diapers, nor do I mind that you use them for what they are intended for. However, what I do mind is the fact that I am having to buy these diapers, that you use, with my money, and that every morning I have to be the one who disposes of them –without our parents knowing- for you.”

“I am fully aware,” Rarity continued, “that as your older sister it is my duty to make sure that I help care for you, and love you, and try my best to make you happy. However, that does not grant you the opportunity to take advantage of me. And perhaps you might see how, given the things I mentioned, that I might feel as though I am currently being taken advantage of?”

Sweetie Belle’s ears drooped as she looked away from Rarity and shuffled uncomfortably.

“I’m sorry Rarity, I didn’t-“

Rarity scooted herself closer to her little sister and wrapped a foreleg around her slim diapered waist, cutting off her reply in the process.

“However…” Rarity continued. “That does not mean I am going to stop providing you with your diapers or helping you clean up after you use them. But it does mean that I am going to need to request a few things from you in return. The main thing being that if I am going to be the one buying diapers, then I should also be able to use them as well.”

Sweetie Belle's surprised stare up at Rarity was not unexpected.

"You...like to wear diapers also?" Sweetie Belle asked, her voice squeaking a bit again.

"You don't think that you are the only filly in Equestria who enjoys wearing a diaper and being able to simply go to the bathroom where ever they are? I have worn them in the past, which I think you know about... though it has been a while. I am aware of how nice they feel."

Sweetie Belle sat quietly for a moment at that and Rarity could almost hear the gears turning in her head.

“But, if you use some of them, and I use some of them…then we will use them up faster. And you will just have to buy more, so how does that save you money?” Sweetie Belle asked.

“As proud as I am that you made that deduction on your own just now, I can see that you misinterpreted my meaning. I never said that I would use my own separate diapers, I mean that we will both use the exact same diaper, every night. If I have to use the bathroom at night I will untape your diaper, go in it, and then tape it back up.” Well, she said it, now she just had to press her advantage.

“Uhh, Rarity?... That's really gro-“

“Now don't you say gross to me Sweetie Belle. You are the one who likes to pee and poop in your diapers on purpose and stay in that messy diaper with your poop squishing all over your butt for the whole night, each night. What I am suggesting doesn’t really make any difference. We are sisters after all, and this is the kind of thing sisters do for each other. And remember, these diapers are technically mine since I’m the one paying for them, so I can do with them what I want.” Rarity said with some force.

“I- I don't know Rarity, its just so… weird.” Sweetie Belle said looking over at the far wall.

“Not stranger than the fact you are using thoes diapers in the first place? I think you might just come to enjoy it.” Rarity continued.

“Besides, I know you are a bit envious about the things Scootaloo is getting to do with Rainbow Dash. Letting me use your diapers isn’t all that different from some of the things they do.

At the mention of Scootaloo’s not-so-secret, secret relationship with Rainbow Dash, Sweetie Belle blushed heavily.

“How do you know about that!? Or how I feel about it? Or-“

“Rainbow is one of my best friends Sweetie. Don't you think we get around to a bit of gossip every once in a while? I know a great deal about what goes on in this town, rather more than you realize, I believe.”

Rarity could see that her little sister’s resistance was crumbling under the realization that there really was no way out of the situation if she had any desire to continue to wear diapers. Rarity couldn't help but smile internally to herself with the realization that she had just made a big step toward her eventual goal of becoming Sweetie Belle’s first true girlfriend. This way she could ensure her sister learned about love and sex in all the right ways long before some other mare or Celestia forbid, a stallion, got in the way.

“Now, I do believe I mentioned that I had more than one ‘request’ to make.” Rarity said before her sister could change the subject in any way.

“If I am going to be able to use your diaper conveniently, then we will have to start sleeping in the same bed again. As you liked to come to my room and sleep with me quite often up until a few months ago, not long before you began to wear diapers, interesting that.” Rarity said almost to herself. “Then I do not believe this will be too much of an adjustment for you.”

“Now, since your bed is the one with the plastic sheet on it, I think I will in fact be the one sleeping in your bed from now on. I could move it to my bed, but then I risk having to answer some potentially awkward questions from mom and dad.”

“I uh, I guess…I don't really have a choice do I?” Asked Sweetie Belle.

“No, I don't suppose you do. I’m sorry if I am pressuring you too much but you need to learn that you can’t just keep taking from somepony without having to give back in some way eventually. Now I can see that its past your bedtime and that you’re tired anyway. It has been a long day after all, now I believe that its off to sleep for the both of us.” Rarity said while giving Sweetie Belle a gentle push off of her bed.

Making her set of conditions to Sweetie Belle at night when the filly was tired was of course part of her strategy, that way she would present less resistance. The last thing Rarity wanted was for the young pony to put up a fight about it and severely complicate the situation. Fortunately that hadn’t happened, and as Sweetie Belle yawned while Rarity followed her shiny smooth diapered butt back through their shared bathroom she congratulated herself on having planned out her timing so well.

As Rarity was climbing up onto the bed after her little sister, Sweetie Belle paused briefly.

“So like, do you have to go now, or…?”

“Well, aren’t we quick to get into the spirit!” Rarity said partially in jest. No, not at the moment, though that situation could well change in the morning.”

“Oh, ok. Well, um, I have to go, so… I guess I’ll go then?”

“Of course, do what you want.” Rarity replied quietly, smiling all the while.

Having been given permission, so to speak, and having no real other option, Sweetie Belle laid down onto the clear plastic bed sheet used for protection against precisely this sort of activity. To be honest Rarity had expected a bit more resistance to her involvement in her sister’s private life -the idea that Sweetie Belle was starting to be old enough to have a private life at all was a strange one- but Rarity was beginning to think that Sweetie Belle was beginning to enjoy the idea of being watched and touched while wearing and using her diapers. ‘She’ll become even more kinky than me some day, I guarantee it,’ Rarity thought to herself.

Rarity’s musings on the future were abruptly cut short as a soft hissing sound became audible in the nighttime stillness of the room. The front of Sweetie Belle’s thick diaper began to darken as an obviously large amount of pee, for a young filly, began to pour into it. Rarity couldn't help but smile down at the young filly.

“Here, let me feel.” Said Rarity as she reached her hoof between the filly’s back legs to press into the soaked padding to be found there. She rubbed up and down over the soft smooth plastic listening to it crinkle quietly. Sweetie Belle for her part, blushed slightly, but instead of resisting, she opened her legs even more widely to allow Rarity’s inquisitive hoof better access, all the while saying nothing. Obviously, Sweetie Belle liked what Rarity was doing, but was not in a mood to admit as much just yet.

“You really do enjoy these diapers don't you, sis.” Her remark really was not a question. It was quite an obvious statement but one that Rarity took no small amount of pleasure in saying. She really was fortunate to have a sister who was already this interested in exploring her sexuality even at this young of an age, even if Sweetie Belle was not at a point where she would think of her actions in such a way.

“Yaaaaahhhhhh….” Replied Sweetie Belle, her response turning into a yawn halfway through. “They’re pretty great.”

“Goodness, looks like somepony really is tired, well that makes two of us then. I think we should both be getting to bed soon, but first there is the matter that we discussed earlier. I need to pee, and there is a cute diaper in need of another good soaking right in front of me.

“So, should I take it off then? That will make it easier for you I guess.” Sweetie Belle said as her newly developing magical abilities began to tug at the diaper tapes.

“Oh, no need for that.” Rarity responded, her more powerful magic preventing Sweetie Belle from going any further.

“I’ve considered the matter, and believe that I have come up with a better way of doing this that won’t require you to take your diaper off every time. That is a rather awkward way of doing things after all.”

“Ok, here is how this will work, sit up and scoot forward a bit, there, just like that.” Now, I’ll position myself like so…” Rarity said as she turned herself around to face away from her sister and hiked her tail up so that her rear end was poised over and a bit in front of Sweetie Belle who was sitting up but leaning back on her forelegs. To minimize the chance that her stream of urine would miss the target altogether Rarity bent her back legs, lowering her rear so that her anus would be just at Sweetie Belle’s eye level. With a gentle pull of her magic Rarity tugged the front of her little sister’s diaper outward a bit forming a gap between the soft white fur of her stomach and the top of the diaper. With the diaper taped up nice and tightly this gap was rather small and provided less of a target than Rarity had considered. Perhaps using her sister’s diaper whenever she wanted to, especially in the middle of the night, was not going to work out very well if the two of them had to go through all of this to make it work every time. Well, she would think of something. Rarity’s first experimental stream was a little high, hitting Sweetie Belle right above her navel and splashing twinkling drops of urine all over her front.

“Oops, sorry. Here, lets try this…” Rarity said while Sweetie Belle gave her a somewhat annoyed look. Her next attempt was perfect and her now more powerful stream arced briefly through the air before disappearing with a faint splattering sound down inside the front of Sweetie Belle’s already wet diaper.

It was hard for Rarity to get a good look at her sister while peeing in her diaper, turned around as she was, but a few careful glances over her shoulder showed her a young filly quite enjoying herself as her eyes were closed and a smile curved her lips upwards. ‘Aha’, Rarity though, ‘she does enjoy this, seems like her earlier reservations will come to nothing then'.

Even though there was little light in the room, when Rarity turned back around to face her sister she could tell the little pony was wearing a quite thoroughly soaked diaper. She was actually rather proud of that diaper, it had not only been well wet in by its wearer, but had then managed to hold up while absorbing a fully grown mare’s worth of pee. Quite fascinating little bit of clothing that. Rarity decided that it might be worth her time to make a more detailed investigation of the construction of these diapers in her design studio.

“So, how does it feel? Rarity asked.

“Um, very warm, and kind of…heavy…” Sweetie Belle responded pressing a hoof into the thick soaked padding between her legs. “Its kinda nice…” She continued hesitantly.

“There you see, I knew you would enjoy it, even though its from me, the pee in your diaper doesn’t feel any different does it.”

“No, I guess not.” Sweetie Belle said happily.

The near giggle in her little sister’s voice was all Rarity needed to hear to know that she had just witnessed the creation of a future lover of pee and diaper play.

“But really now, we must be going to bed.” Rarity said before either of them could come up with new ideas which would put off bedtime until it was even later at night.

As the nights were warm this time of year the only thing Rarity bothered to pull over the two of them was a thin sheet. Nothing more was necessary, especially as Rarity couldn’t help spooning with her little sister. The temptation to have the warm, wet bulk of Sweetie Belle’s soaked diaper pressed up against her, just above her most sensitive areas was simply too much to resist.

“Good night Beautiful, I love you.” Rarity whispered as she kissed her wet little sister behind her ear.

*** The Present ***

The faint sound of a door opening a level below and on the far end of the penthouse accompanied by a faint “Rarity, I’m back.” Told Rarity that Sweetie Belle had returned from… wherever it was she had had to go off to in such a hurry. Rarity couldn’t really say she had been annoyed by her younger sister’s sudden unexplained departure. After all, if Rarity hadn’t found Sweetie Belle’s hastily abandoned diaper laying lonely on the floor of her bathroom, she wouldn’t be experiencing the pleasure of wearing it now.

Though the fact that Sweetie Belle was suddenly back, and Rarity, not only being in a position difficult to get out of, - How does a mare hide the fact she stole her younger sister’s messy diaper out of her own bathroom? – but being exceptionally horny due to the aforementioned diaper, decided without really realizing it, to reschedule her planned night time activities to this afternoon with the added benefit of a messy diaper she had not counted on possessing.

Mind made up, Rarity turned herself over and with surprising grace for a mare in an outfit both quite bulky between the legs and overall constricting hopped off her sofa and glided over to a large custom built hutch made of a fine dark wood which was a smaller version of an even larger one downstairs in the main kitchen. Opening one of the top drawers, Rarity removed a small nondescript metal container out of a number of other random items filling the drawer and from that container she removed a small light blue candy. At least it was made to look like a candy, the thing didn't taste as nice as a piece of candy ought to but the effect it had on a mare was even more sweet. At least in her opinion.

The supposed candy in question was actually the result of a joint project going on between her and her close friend Princess Twilight Sparkle. Even though as dear friends there was never any real reason for her to bother with thinking or even saying Twilight’s formal title, Rarity always took a bit of prideful pleasure at being able to call a true alicorn princess of Equestria a close friend.

In Rarity’s line of work, outside of the fashion industry that is, there is a very high demand for any mare who possesses, either temporarily or permanently, a fully functional male member. This ability almost exclusively tended to be the domain of unicorn mares due to unicorns possessing the most obvious active magical abilities. The problem was that any sort of true anatomy-modifying magic is extremely difficult to do correctly and requires great skill and practice. It was to Rarity’s great joy, then, when she found out from Twilight that alicorns, namely the four modern princesses of the known world, could preform this sort of magic with considerable more ease and with much better results than even an experienced unicorn.

It was even better knowing that the ancient magical process Twilight used had not only been greatly improved upon by Celestia in millennia past for the purpose of pleasuring her younger sister Princess Luna, but had then been adopted and all but perfected by Princess Cadance, the Princess of Love. Who better to make a great spell perfect than her?

Rarity knew first hoof just how great a spell it could be after being made to feel like a young filly again by being rutted hard with the thick shaft of an alicorn princess. Despite being hesitant at first Twilight had really taken to the role of using Rarity as her test subject for determining which variations of cock length, diameter, and even curvature were optimal.

It had been Rarity though, who had suggested that Twilight could prove invaluable at helping her find a way to allow even a simple unicorn mare to experience what it was like to possess for herself a hot thick shaft. It had taken over a year of development, more than a dozen trips to the Everfree Forest for magical plant specimen collection, and a few suggestions from Cadance to develop a powder that, when ingested, would grow a surprisingly functional and complete male reproductive system while preserving the full use of a mare’s natural female parts at the same time. So far they had managed to refine the process such that only a small amount of the power was necessary to maintain the effect for over a day. This then was the amount used in each of the candies which Rarity was so careful to keep inconspicuous in her drawer. It was not as though there were any known negative health effects of the things, but there was simply something about the idea of her gorgeous little sister having a cock and balls waving around between her legs that made Rarity somewhat uncomfortable. She preferred Sweetie Belle to maintain her purely natural and unmodified female form for now. There was a certain beautiful innocence, almost a form of virginity about it that Rarity was not yet willing to allow to be removed. Besides, Rarity felt it was important for any mare, especially for one as beautiful as Sweetie Belle to learn to love herself just the was she is. Only after learning to fully appreciate one’s natural beauty should a mare earn the right to start playing around at changing their physical form. That much Rarity believed anyway.

None of this however, prevented Rarity’s joy at being able to use her modified anatomy on her younger sister’s natural form.

With a single swift motion Rarity tossed one of the rare and extremely valuable blue candies into her mouth and swallowed. Smiling to herself she trotted out of the sitting room and over to her bedroom door which she eased open to gaze out down the hall with its plush blue white and blue diamond patterned carpeting and lighted alcoves filled with fine porcelain vases.

“Sweetie Belle, when you have a chance, could you be a dear and please come to my sitting room. I would like to have a talk with you.” Rarity called down the hallway.

“Um, ok, but give me a chance to make lunch first.” Came the reply from somewhere near the kitchen, Rarity thought.

“Of course, and thank you!” Rarity called back, closing the door again.

As she crossed the distance back across her large bedchamber to the sitting room again she couldn’t help but let a bit of a private grin show on her face as she began to feel the presence of her new and still growing stallionhood and balls squish their way into the sloppy mess filling her- no, her sister’s diaper. That combined with the shiny black pvc catsuit tightly covering her body made her quite certain she was going to enjoy this afternoon no matter what.

*** 4 years and 364 days ago***

When Rarity awoke she could immediately tell that it was still early morning. The color of the clear sky seen through Sweetie Belle’s bedroom window meant that the sun was just starting to climb above the horizon. Rarity did not usually feel so awake so early but she had gone to bed earlier than usual as well due to having to operate on her little sister’s sleep schedule. The next thing Rarity became very aware of was the presence of Sweetie Belle laying next to her on the bed. As expected, the both of them had shifted around in their sleep so they were no longer in the spooning position they had been in upon going to bed. However, they were still in contact. Rarity was laying on her back with Sweetie Bell laying on her side facing away from Rarity. Sweetie Belle was however laying right up next to Rarity so that her diapered behind was pressed up against Rarity’s hip.

The first thing Rarity realized as she became aware of the feeling of her sister’s diaper rubbing against her was that said diaper seemed to have a large soft bulge in it that she did not remember feeling when she had gone to sleep. The second was the smell. It was hardly overwhelming, but it was there. The definite aroma of a messy diaper. Rarity could feel her heart begin to beat a bit faster from excitement. Sweetie Belle had done just what Rarity had hoped she would; turn a wet diaper into a messy one.

Rarity shifted herself a bit to feel her hip press into and rub over the large pile of soft poop filling the back of the young filly’s diaper. Even such indirect contact felt so good. The next step then, was to reach her leg down and use her hoof to press into the full seat of Sweetie Belle’s diaper directly. She could feel the soft mess deform under the pressure and squish outward a bit from where it had all been.

Sweetie Belle stirred a bit and whispered a muffled “Good morning Rarity.” As her face was still partially buried in her pillow. Rarity decided that she really couldn’t resist any further. She could feel her increasingly sensitive pussy beginning to leak a bit of mare cum down her thigh, which was a good indication that getting back to sleep was an impossibility at this point. Though Rarity did pause a second and wonder how it was that she had gotten to this point. Was she really so turned on by her sister in a messy diaper of all things? A mare having a sexual attraction to her sister, while not the most openly discussed topic in Equestria, was hardly unheard of. Rarity supposed it was the juxtaposition of it all, a beautiful, healthy, filly living in a clean home with a nice family purposefully going out of her way to enjoy such a filthy smelly mess between her legs without any actual need to do so such as some medical condition. It just drove Rarity a bit wild. Perhaps her constant attention to professionalism, appearance, and sanitation in the rest of her life was proving a bit much for her subconscious to take. Something had to give, and diapers proved to be that outlet.

Rarity folded the rumpled sheet they were both still sleeping under back down to the end of Sweetie Belle’s bed. She was rewarded with the sight of her little sister laying on her stomach on top of the clear plastic bed cover, back legs spread open by a bulging bloated diaper so thoroughly soaked not a bit of padding remained dry. The diaper was mostly a slight yellow color but with an obvious brownish stain covering Sweetie Belle’s butt. Rarity’s state of excitement grew even more urgent as she considered what it must feel like for the filly wearing these diapers. Perhaps she should try to find some diapers in a size that would fit her some day.

Not being able to hold her desires back any longer, Rarity positioned herself over her little sister’s still sleepy body so that her dripping pussy was right over the thick wet and messy diaper below. With her heart thudding in her chest she lowered herself slowly down until her wet lips and clit made contact with the smooth warm plastic of Sweetie Belle’s diaper. She continued by letting her back legs fully relax, allowing her full weight to settle down on the soggy, dirty diaper. Rarity sighed with bliss as she felt the large mass of poop spread out inside her sister’s diaper from the weight of her body. Even through all the soggy padding Rarity could feel the squishy shit provide lubrication between Sweetie Belle’s butt and the diaper allowing it to slide around her backside more easily as Rarity began to rock back and forth.

“What are you doing Rarity?” Asked Sweetie Belle who was trying but failing to turn over due Rarity’s full weight keeping her in place.

Rarity now had her inner thighs pressing firmly against Sweetie Belle’s hips as she slid her wet slit up and down her sister’s messy diapered butt. It felt so warm and slick, a better sex toy Rarity could not imagine.

“I’m enjoying feeling your diaper. Doesn’t it feel nice? I know you like to mess your diapers so I don’t think this is much different.”

“I like it, it does feel…nice.” Sweetie Belle said as if trying to come to terms with the fact that she actually believed what she had just said.

“Don't worry about a thing dearest, just let your big sister make you feel good in your diaper.” Rarity said, now pressing her dripping slit against the poopy diaper and moving her hips about in small circles.

As Rarity’s hip thrusts against the messy diapered filly between her legs became more and more frantic, the smell coming from the diaper became even more noticeable. This only drove Rarity on to new heights of pleasure. Her only regret at this point was wishing she had decided to try this a few weeks earlier. No matter though, she would simply have to make up for lost time.

The feeling of having her clit in direct contact with Sweetie Belle’s beautiful diapered butt, the smooth warm plastic stretched tightly over the thick urine and poop filled diaper padding, not to mention the adorably filly wearing the wonderfully disgusting thing proved too much to allow Rarity to control herself. With a loud groan she came all over the butt of her little sister’s diaper, forcefully squirting clear mare cum between her inner thighs and the diaper between them. Even after cumming Rarity couldn’t help but keep going for a bit, smearing the clear sticky fluid all over Sweetie Belle’s diapered backside.

Panting, and feeling weak in all her legs, Rarity plopped herself down beside her little sister and gazed lovingly at the beautiful diaper that had just brought her to such an unusual but wonderful orgasm. Now the seat of the diaper truly showed what it contained. The once mostly light yellow color had been replaced by a shade of light brown that covered the whole of the back of the diaper. Rarity’s motions must have done a very good job of squishing that poop all around.

Being the young and fit mare that she prided herself on being, Rarity was not one to call it quits after only a single orgasm, especially not when she was this horny. Besides, after having cum her body had settled down enough to make her aware of a new and, due to current circumstances, welcoming sensation. As expected, it was time for her to make her usual morning poop, however on this occasion she had something wonderful planned for it. She was going to put her mess to an even better use than on thoes occasions where she collected some of her typically delightfully runny poop on her hoof and smeared it into her pussy. This morning however, her waste was going toward a higher purpose.

“Seems like you enjoyed that as much as I promised you would.” Rarity said to her sister as she rolled over onto her back now free of Rarity’s weight.

“Yah, that was fun! It feels really good in my diaper now, can we do that again?” The excited filly asked.

“Not the same exact thing no, but I have something even better planned.” Rarity said with a grin. This was going to be fun.

*** The Present ***

As Sweetie Belle crossed the plush purple carpet of Rarity’s bedroom and up the two steps separating it from the attached private parlor Rarity made sure that her sister got as good a look of her sleek black pvc encased body as she could manage, alternately stretching her fore legs, then hind legs, and arcing her back to thrust her padded butt into the air before settling down on her stomach. Legs outstretched in front of and behind her.

“Wow sis, your hot. As usual.” Sweetie Belle stated bluntly, not bothering to tread lightly around the mare who knew every secret she possessed, and who’s secrets she knew equally well.

“Complements are all well and good dear, but they won’t get you out of a talking to this time I’m afraid. Now, I have a keen sense of smell as you well know. Therefore, I was quite aware of what it was you were doing right before you left to go out with, Applebloom, I’m guessing?”

“Yah, it was her.” Sweetie Belle responded beginning to look a bit embarrassed as she realized the direction this discussion was going to be going in.

“And was this something you scheduled beforehoof?” Rarity inquired with a raised eyebrow.

“Yes, we planned it, but-“

“No buts.” Rarity interjected before her sister could attempt an excuse.

“Now, back to what you were doing before you left with Applebloom. Again, as I said, I have a good sense of smell, and can you guess where that sense of smell led me to only a few minutes after you left? Right to your bathroom. And before you complain about that, let me remind you who’s apartment this is. I own every room in this place and will exercise my right to enter any one of them at any time I choose. So, tell me what did I find in your bathroom?

Sweetie Belle fidgeted uncomfortably a bit but after a second of hesitation said; “One of my diapers.”

“Yes, One of your diapers, which I custom made for you.” Rarity replied.

“And tell me, what state was that diaper in?”

Again, more fidgeting.

“It was…used, wet and messy.” Came the younger mare’s response, minus any eye contact.

“Correct, wet and messy. Very, very, wet and messy. Just as it should be. However, I distinctly recall seeing you in the downstairs living room less than an hour before you went off with Applebloom, and I also distinctly recall that you were not wearing anything aside from that black rubber choker you are so fond of.

“This means, that all within less than one hour you put on one of the beautiful diapers that I made for you, used it very well, masturbated in it, -I see no other explanation for the sticky clear fluid mixed in with all the poop- and then took it off to go out with your marefriend for the afternoon. An event that you planned well in advance, which also means that you had no intention of wearing that diaper for more than, what, half an hour at most?

By this point Sweetie Belle was sitting down and her ears were drooping but Rarity was not finished.

“I know I’ve said this before but it seems that I will have to say it again, when you are wearing and using a diaper I made for you, you are wearing a gift from me, a symbol of my love for you. I am well aware that even the best diaper cannot last for ever and can only hold so much, but only wearing a diaper of that quality for half an hour is downright disrespectful both to the diaper itself and to the pony who made it, in this case, me!” When you choose to put on and use one of thoes diapers you are making a commitment that you will enjoy it for a whole day at least. I will accept nothing less. And if you can’t find it within yourself to enjoy my creations to the extent they were designed and intended for then I will stop making them!”

Despite being quite miffed, almost bordering on actual anger, the sight of her beautiful sexy sister sitting there with her ears flat against her head and tears forming in her eyes nearly broke her heart.

“Sigh… I’m sorry I raised my voice at you, its just that you should know by now how important this is to me, and anyway we have had this discussion before, so it bothers me that we have to have it again…”

“Fortunately for you, Sweetie Belle, the situation is not as bad as it could be as I happen to be a very resourceful mare. Here, have a look.”

As she spoke Rarity sat up on her sofa enjoying the squishing of the thick layer of her sister’s mess spread liberally between her legs and all over the newly formed appendage laying there. Once sitting upright, she reached up just beneath her chin to find the zipper tab concealed beneath a flap of pvc material and began to tug it down. The zipper line only extended partway down her chest and was designed to provide only the minimum available opening to allow a pony to put on and remove the garment. After all, one of the points of a good catsuit of any material is to be as seamless as possible. Rarity would never accept a zipper line that extended though the crotch, it ruined that smooth seamless appearance she was looking for.

Fortunately for the sake of appearances Rarity had spent time practicing getting out of the garment with the greatest grace possible. It helped to save face, especially in times like this. After using her magic to tug her last leg out from the outfit and carefully laying it out on the sofa, Rarity sat herself heavily back down with a wonderful squish and spread her legs to give her sister the best view possible.

“Now do you understand what I mean by ‘resourceful’?” Rarity asked the now smiling young teen mare before her.

“That’s my diaper, you’re wearing my used diaper…That is so totally gross, but kinda hot…” Sweetie Bell said blushing but not able or willing to look away from the extra bulky disposable diaper with light pink plastic covering and miniature versions of her cutiemark dotted around the top of the front. The way its absorbent padding was so heavily stained by the underlying goopy mess, apparent even through the diaper’s thick pink plastic was obscenely sexy, especially considering that the mare enjoying the mess was not the one who had created it.

“Yes, Sweetie Belle, it is. I have figured out a way of ensuring that you will receive a proper amount of enjoyment from this diaper. Now, quit your sitting around on the floor and get up here.”

Rarity guided her younger sister’s movements as she climbed up onto the sofa and over herself, as she was now laying on her back wearing only Sweetie Belle’s diaper with her head propped up on a cylindrical pillow. As soon as Rarity saw her sister’s rear positioned correctly she commanded Sweetie Belle to sit down. As the younger mare did so, her now wet, Rarity noticed, pussy and anus came to rest directly down on the front of her diaper. However, that was not the only thing they came down on top of. Rarity had to stifle a moan as her thick cock, already smeared in her little sisters’ shit was pressed down upon by the weight of a hot teen filly.

Sweetie Belle’s eyes grew wide as she suddenly recognized that she was feeling the presence of a large stallionhood under the surface of the bloated diaper. Rarity smiled up at her as she watched her sister’s reaction.

“You see, I think there are a few things you can do to help me out this evening.” Rarity said with glee.

*** 4 years and 364 days ago***

“The first thing I am going to do is untape the front of your diaper, but I’m not going to take it off you, just sit back and relax.”

Rarity quickly went about doing as she said she would, the moment the filly had leaned back into the pillow behind her. Her magic made swift and precise work of the four blue tapes on the front of the soaked diaper and within seconds Rarity was able to pull the thick wet padding forward with a light crinkling sound and let it plop down on the plastic sheet between Sweetie Belle’s legs.

For a few seconds Rarity simply sat and stared at the beautiful light pink slit peaking out from below her sister’s tail. While the filly in question was still too young for her to get wet with mare cum the urine matting down the fur between her legs also provided a glistening layer of fluid over thoes beautiful pussy lips that sparkled in the sunrise, this made for an equally enticing lubricating fluid. What made Rarity all the more excited was the presence of a thick layer of light brown poop with a somewhat runny consistency beginning to creep up from the bottom of the diaper. It was just beginning to come into contact with Sweetie Belle’s young slit.

‘Good’, thought Rarity. ‘Her mess hasn’t come up into the front of the diaper much yet. I’ll have more effect that way.’

“Now sit still Sweetie Belle, I think you will enjoy this.” Rarity said as she turned around and positioned her rear directly over her sister’s cute little slit. As soon as she felt her position was as good as it was going to get she released her control over her anus and was rewarded with a wave of released pressure as her morning poop rushed out of her and right into the front of Sweetie Belle’s waiting diaper with a soft ‘plop’. As she turned around Rarity could see that her aim was perfect as not only was the big soft pile of brown mess centered square in the middle of her sister’s open diaper, but it had landed partially on top of that beautiful pussy, now no longer visible, buried as it was under the huge pile of her her bowel movement.

The look on her sister’s face was an interesting mixture of fascination and disgust.

“Eww, Rarity, that's super gross, I didn’t know you were going to do that-“ Sweetie Belle said as she reached out a hoof to touch the gently sagging pile.

“Now, you just wait a second, wait for the next part before you get ahead of yourself.” Rarity said, blocking her sister’s inquisitive hoof.

Rarity smiled even more broadly as she slid both forehooves under the front of her sister’s diaper laying out on the bed and slowly lifted it up, pressing it into place against her and using her magic to once again securely fasten the tapes pulling the front of the diaper tight. Rarity knew she had won Sweetie Belle over as the the little filly closed her eyes and sighed as the huge mass of her older sister’s poop was pressed firmly against her and squished between her young delicate pussy lips.

‘Sweet Celestia’, Rarity thought, ‘that was beautiful. I just might have to try that for myself.’ She shuddered internally at the unquestionably disgusting thought, but somehow, after seeing her sister enjoy it, it didn’t seem so bad. And besides, what kind of sister would she be if she did things to her younger sibling that she wasn’t willing to do to herself?

Before she could really stop to consider what she was doing, Rarity couldn’t help but act on a sudden impulse to bury her face in the bulging, stained, poop filled front of her little sister’s diaper. Sweetie Belle let out a little squeak of surprise and then a giggle of laughter as Rarity alternately kissed and licked the smooth plastic crotch of the extra messy diaper. The smell was awful, but that just made Rarity’s pussy leak cum down her inner thighs all the more.

As she pressed her muzzle and tongue against the slick plastic of the filly’s diaper, Rarity could feel the pressure she applied spreading and squishing the mess around underneath. It was driving her a bit crazy she admitted. She had already cum on the back of this diaper, perhaps she could do the same for the front? Though she wanted to do something a bit different this time. Besides, it simply wasn’t fare for her sister to be enjoying all this mess for herself. As usual with Rarity, inspiration struck. Telling her sister to stay where she was. Rarity leaped off the bed and hurried back through the interconnected bathroom and into her own room, not seen since the previous night. As she was a well organized pony, Rarity had no trouble locating precisely what she was after.

Returning to her sister’s bedroom with one of her favorite pairs of shiny black rubber panties, Rarity was happy to see Sweetie Belle enjoying pressing her hoof into the heavy, now somewhat flattened out, bulge in the front of her diaper. Even though the little filly probably couldn’t achieve orgasm yet, something Rarity really ought to test one of these days, she was still obviously making herself feel good through the thick padding. Without wasting any more time Rarity hopped back up onto the bed.

“Here, let me help you with that.” Rarity said as she reached out her foreleg, pushing her sister’s own aside. Starting from the bottom of her sister’s crotch, Rarity applied more pressure that she would have needed if simply rubbing was her goal, and pressed upward. Pressing her hoof upward, Rarity was pleased to see a bulge of poop pile up under the diaper ahead of her moving hoof. When her hoof neared the top of Sweetie Belle’s diaper the bulge squished its way out the top of the diaper and onto Rarity’s waiting hoof. The process left an obvious brown smear along the top edge of her sister’s diaper and in the fur around her navel.

“Why’d you do that?” Sweetie Belle asked, “I don’t want to make a big mess…”

Rarity gave her a ‘bit too late for that’ look but didn’t say anything.

“I meant outside of the diaper!” Sweetie Belle said blushing slightly.

“Don’t worry sis, that’s all the mess I need to make, at least so far as you’re concerned.” Rarity said smiling more to herself than for her sister’s benefit.

Taking the big glob of her own poop that until then had been so comfortably sitting in her sister’s diaper, Rarity began to smear it all around the inside of the crotch of the tight rubber panties that she held open with her magic in front of her.

Understanding dawning on her face Sweetie Belle began to giggle as she watched her older sister trying to get as much of her mess as possible off of her hoof and into the inside of her panties.

“Hehe, you like the feeling of poop on you too! I knew it! You’re jealous of my messy diaper aren't you?” Sweetie Belle asked still giggling.
Why was it that siblings could be at their most perceptive only at times when that perception could cause the greatest embarrassment? Rarity asked herself, trying not to make eye contact with the laughing filly.

“You’re one to talk.” Rarity grumbled, wiping the remaining mess off her hoof and onto the front of her sister’s still bulging diaper.

While the still smiling filly watched, Rarity delicately took the rubber panties with their now very messy crotch and pulled them up her back legs being careful to not leave any obvious streaks of poop up the white fur of her calves. The feeling of having the pile of now slightly cool moist shit squish itself into her dripping pussy was every bit as awful and as wonderful as she had hoped it would be. No wonder Sweetie Belle liked her diapers so much, Rarity couldn’t think of any other lubricant she could apply to her lower lips that would feel half so good.

Shuddering from the intense sensation of the tight smooth panties hugging her hips and butt, not to mention the mess they held pressed tightly against her, Rarity laid down on her back and scooted her butt forward until the black shiny tight crotch of her messy panties made contact with the stained off-white thick bulge of her sister’s diaper. Moving forward a bit more made her little sister’s diaper press firmly between Rarity’s legs and squished the mess around in both of their respective garments.

Rarity moaned as she felt her shit being forced between her dripping lips and around her clit. How she was supposed to ever fully clean herself up after this she didn't know, but at the moment she didn't care. Normally Rarity prided herself on being a mare in full control of her body, when she came it was precisely when she wanted to, and not before. But this time everything was so new, so stimulating, so nasty, and so erotic. It wasn’t just sex with another mare for money this time, though she would never say she didn't enjoy such things, it was just all so new. If it hadn’t been for meeting Princess Cadance two years ago and being shown just how diverse pony sexuality could be, she would never have been suspicious of Sweetie Belle’s desire to wear diapers, which meant she would never have gotten to this point in her relationship with her sister.
As the intensity of her shit smeared orgasm overcame her, she groaned loudly feeling the brown slop work its way up her vagina. As her cum splashed out into the crotch of her tight rubber panties, some back part of her mind decided that she would have to thank the Princess of Love some day for this when she got the chance.

‘No better than some dumb stallion.’ Rarity thought to herself as the blinding pleasure of her orgasm died away. She hadn’t been rubbing her pussy on her sister’s diaper for even a single minute before she lost control. If it felt this great without even wearing a diaper and only having a hoof full of poop in her panties how good would she feel with her entire crotch and butt swimming in the stuff, surrounded by thick pee soaked padding? Right then and there Rarity resolved to herself that she would either find, or make, quality disposable diapers in a size that would fit her. And the next time she had a session with her sister like this the both of them would be well padded and totally messy.

The current situation though, was far too stimulating for only a single orgasm to suffice. In no way could she be finished. And besides, Sweetie Belle sitting there, back legs outstretched before her and thick shit filled and smeared diaper taped tightly around her waist squishing two hot loads of poop into all her best places, was simply too adorable and hot to resist playing with.

Making the filly squeak in surprise, Rarity lifted her completely off the bed in a gentle yet firm magical field and set her down so she had both sets of legs on opposite sides of Rarity’s head. Gazing up at the underside of her sister’s filthy diaper Rarity licked her lips in anticipation.

“Please Sweetie Belle, do your sister a big favor and sit down on her face in that lovely diaper you have on, its so beautiful.” Rarity said quietly as she reached up a hoof and gently stroked the brown stained, bulging crotch of the diaper hanging over her.

“Um, ok, here goes…” Sweetie Belle said, giggling again. What a wonderful sound that was for Rarity, nothing was better than a happy sister.

As the filly’s diaper, now little more than a thick poop and urine filled bag pressed itself down, covering Rarity’s eyes, and nose, and rubbing against the hard shaft of her horn, Rarity smiled in the darkness under the squishy, smelly padding and decided, as Sweetie Belle began to rock backward and forward in her mess, that she had the best little sister in the world.

*** The Present ***

Rarity watched on happily as her young teen sister came with a rather un-feminine yell while sliding her wet slit up and down the length of the long bulge Rarity’s cock formed in the front of her diaper. No matter how thick and wet the padding, her hard stallionhood always easily had sufficient girth to become notable through her diapers. Or in this case through her sister’s. Feeling her sister’s weight slide along her shaft with Sweetie Belle clamping her inner thighs around Rarity’s padded hips was such a wonderful feeling Rarity simply wanted to squirm in delight like a little filly.

“Now see, and here I was starting to believe you didn't like your own diapers.” Rarity said in a gently mocking tone.

Sweetie Belle stabbed her sister with a reproachful look while panting from her prior exertions, but declined to escalate the discussion with even more intense sarcasm.

“Its, not just your- my- diaper that I’m enjoying, you have something underneath that you know I very much want to have.”
Rarity grinned like a cat with the proverbial mouse.

“Oh, do I?” Rarity asked with rather insincere confusion. “Well, if you want it so much would you at least like to see it? I’d love to show it to you.”

Sensing that Rarity was not about to take no for an answer to her question and having little if any desire to respond in such a negative manner herself, Sweetie Belle scooted backward off of what used to be her diaper. As soon as Rarity was free of the overlying weight of her sister she began to slowly remove each of the diaper tapes individually, drawing out the process as a way of teasing her expectant sister.

As the last of the tapes released their hold on the front of the diaper, Rarity peeled the extra thick padding back allowing her throbbing cock to stand up high and proud. The normally smooth creamy white skin of her dick and equally shiny black skin pulled tightly around her heavy balls were each fully coated from head to base in a liberal covering of runny, light brown shit that slowly dripped down the length of Rarity’s long thick shaft, glistening in the evening sunlight. The sudden exposure of her wet stallionhood to the cool air of the penthouse made her shiver and her throbbing pussy, hidden under her heavy balls, began to leak even more.

The now unfolded diaper was a virtual sea of goopy light brown muck and it made Sweetie Belle wet just imagining how it must feel to have had both a pussy and cock surrounded and coated in so much beautiful scat. Then she realized again with a start that what she was looking at was her own mess in her own diaper from just that afternoon. And indeed she again felt guilty at having abandoned such a wonderful mess, even if it had been to go out on a date with Applebloom. Had she really pooped and peed so much as to result in this? Had Rarity added to it?

“Take a good look Sweetie Belle. This is all yours, I haven’t added a thing to this diaper… yet.” Rarity said, gesturing to the general mess, even as her teen sister held up a foreleg across her muzzle in a futile attempt to relive herself of the stench, which she was starting to think would burn the inside of her nose. Sometimes she wished ponies didn't have such a good sense of smell.

Despite her reaction, Rarity was proud to see her sister smile from behind her leg. Sweetie Belle was the love of her life and being able to please the constantly horny teen was an endless source of pride for her. Besides, there was no way in Tartarus she was ever going to let her pure, innocent, technically virgin, sister get anywhere near a true stallion until she was ready to settle down and take the time necessary to properly help raise a family, a time that was hopefully at least twenty years away. And even then, Rarity would rather her sister find a nice mare to settle down with, like Applebloom, besides, with the magical knowledge of this modern day and age a male pony was not strictly a prerequisite for having a foal any longer. The only pony who had functional male equipment that she was going to let Sweetie Belle get anywhere near was herself. Though perhaps letting her dear friend Twilight, or even her recent sexual mentor Princess Cadance, have a go at the teen filly’s wet slit would be fun to watch. She still wasn’t convinced Cadance could fit though.

Movement from Sweetie Belle brought Rarity back out of her thoughts, and she watched the younger pony stand up and move herself over Rarity, or more importantly, over her hard, shit smeared shaft and then line herself up properly.

“Um, may I?” asked Sweetie Belle as she realized, blushing, just how forward her actions seemed.

“Do you think I went to all this trouble only for you to see it briefly before I hide it away again in my- your- diaper? Hardly, I want you to, beg you, to fuck your gorgeous body with it as much as you can stand. Please, go ahead, its all slimy and lubed up with your own mess, you can’t find a smoother ride than this in all Equestria!”

Laughing, Sweetie Belle did as was suggested and set her pristine, glistening, light pink slit right on the tip of Rarity’s cock, smeared in the scat of the filly who was going to fuck herself with it. ‘What beautiful irony’ Rarity thought at the scene before her. Relaxing the muscles in her back legs, Sweetie Belle eased herself down the long thick girth of Rarity’s shaft. The feeling of being so completely filled and having her own slimy mess act as the lubricant between the already smooth skin of her older sister’s dick and her wet vaginal walls made both her and Rarity moan continuously through the whole process. Rarity only felt her sister stop sliding downward when she realized the tops of her balls were being squished up against Sweetie Belle’s anus. Even though it was not the first time, Rarity was so proud that her sister had the capacity to take the whole thing inside of herself while remaining so wonderfully tight. Truly the capabilities of the teen pony’s muscles were a wonder.

For the first minute they both simply stayed still, enjoying being connected at such a basic level. For Rarity, a mare, to know what it was like to be inside her own sister. Well, that was truly a gift handed down from Great Faust, or perhaps from one of the lesser Elder Gods. Twilight would undoubtedly know, ancient religions were among her many interests. When Sweetie Belle began to lift herself up and press back down all thoughts of near forgotten faiths fled Rarity’s mind. With the right consistency, scat really could be about the perfect lubrication for sex, mixed with a bit of urine the result was a wonderfully slimy and slick glistening paste that felt unbelievably good when in contact with any sexual organ. That’s what made wearing a messy diaper for long periods such a joy. Doing so, she could practically bathe her nether regions in the stuff all day, which kept her feeling gloriously horny for much longer than she otherwise would have been able to.

Sweetie Belle’s increasingly swift pumping up and down on Rarity’s thick cock was making coherent thoughts difficult. With each downward push Sweetie Belle made a different kind of grunt or squeak and the force of the motion made Rarity’s butt audibly squish about in the thick layer of her sister’s mess in the back of the diaper. Rarity could be a bit of an aggressive mare both in daily life and in the bedroom, or wherever she chose to have sex, so it was nice every once in a while to simply lay back and let her sister do all the work. Rarity enjoyed watching her little sister’s shit smeared pussy lips glide effortlessly up and down, eagerly taking in the entirety of Rarity’s hard shaft. And with each downward thrust of Sweetie Belle’s hips the sudden contact of her butt with Rarity’s crotch made a loud slapping/squishing sound that she found quite naughty.
With her front legs holding onto Sweetie Belle just above her hips, Rarity was able to guide her little sister into a circular pumping motion not unlike the movement of the coupling rod on the wheels of a steam locomotive. After only a few minuets of this, Rarity was reaching her limit, she could feel the wonderful pressure building at the base of her dick as Sweetie Bell’s hungry pussy once again fully engulfed the thing.

“Oh Sweetie, dear…I’m almost there… I going to cum inside your sweet body.” Rarity moaned not having the breath necessary to properly speak her words.

“Please sis…cum in me so hard…” Sweetie Belle replied equally as breathlessly.

Rarity didn't need any more excuse than that, as she felt her her cum flow up her rock hard shaft and erupt out her head as it pumped thick ropes of creamy white fluid that splashed against her sister’s cervix. More and more cum kept squirting out of her until it began to squish out around Sweetie Belle’s pussy lips and the base of Rarity’s cock. At some point while Rarity had been lost in orgasmic bliss, her younger sister had came too, squirting out a spray of clear slightly sticky fluid that mixed with the brown scat spread all over to drip down and over Rarity’s large smooth black balls.

Rarity didn't think she had ever been able to sustain an orgasm for quite so long before. Certainty this was not the first time she had fucked her little sister with her own stallionhood, nor was this the first time doing so while her cock was coated in the contents of a messy diaper, but it was the first time said diaper and contents had previously belonged to her sister. That brought the intimate kinkiness of the whole endeavor to even greater heights.

Having finally spent all her energy on top of her older sister’s cock, Sweetie Belle had fallen forward and was now comfortably laying on Rarity’s chest with her horn tucked under Rarity’s chin. Fortunately for Rarity, this position had allowed her still solid shaft to remain buried deep into her sister’s hot wet vagina. Rarity knew just how to take advantage of such a situation and she had prepared for it well by not using the bathroom for some time before her little sister had returned home. While in the throws of passion the urge to urinate had all but disappeared, but now it came back with almost painful urgency.

‘Alright bladder, this is your time to shine.’ Rarity thought as she fully relaxed herself. Almost immediately a hot torrent of piss rushed up her hard cock and exploded against Sweetie Belle’s cervix, just as her cum had minutes before, with such force Rarity could hear it through Sweetie Belle’s body.

Sweetie Belle instantly opened her eyes wide as Rarity’s hot urine gushed into her vagina and began to squirt out around the base of Rarity’s cock making a warm cascade around her balls and over her anus before disappearing into the layer of warm shit and diaper padding beneath Rarity’s well rounded ass.

Rarity had no fear that her sister would be angry, as this was not the first time she had pissed into her sister after sex, but she was surprised at how the teen mare, so calm and quiet before, sat back up as quick as she could blink and began feverishly fucking herself on top of Rarity’s still pissing dick, sending droplets of urine splashing about all over.

In only a minute the half crazed filly had brought them both to orgasm a second time making Rarity extremely glad she had done what she had planned to do. Apparently cumming only once was no more acceptable an outcome to Sweetie Belle than it had been for herself.
Several minutes later, Rarity found herself sitting upright working on taping her sister’s now much more thoroughly soaked diaper back up tightly around her waist and still hard cock. It may not have been as exquisite a feeling as being buried balls deep in her own little sister, but having her cock once again squishing firmly into the thick layer of scat covering almost every part of the inside of said sister’s super messy diaper was heaven in and of itself.

“Ugh.” Muttered Sweetie Belle sitting opposite Rarity at the other end of the sofa. She had her legs spread wide open and was pushing a hoof experimentally at her pussy.

“My pussy is going to smell awful for the next week.” She groaned as she watched a few more drops of brownish fluid leak out and disappear underneath her butt.

“Oh, but that’s all part of the fun!” Rarity said as she completed adjusting her sister’s messy diaper around herself.

“It will keep reminding you of what we did this evening, and that will keep you feeling horny.”

Looking up from her leaking pussy Sweetie Belle raised one eyebrow at Rarity yet said nothing.

“Well, if you don't like it I’m sure there is some magical ways to get your insides thoroughly cleaned up but where’s the fun in that? Having a pussy that constantly smells like a messy diaper is one of the better pleasures in life and will show you who your true friends are when they go to lick it.” Rarity said with a shrug.

Sweetie Belle could only laugh and shake her head. Even after all they had done together Rarity’s kinky side still managed to surprise her.

“So.” Rarity said while looking up, suddenly sounding a bit more serious than before.

“I know that for some time now you have been wanting to accompany me on one of my nightly excursions about Canterlot, see what all the city has to offer and all that. I’m not going to take you just anywhere, there are certain types of fetish clubs which even I don’t want to go to, and some I’m not even allowed in, but if nothing else there are a number of mares who I think you should get to know, and who want to get to see you. I know that for a fact. After seeing you so willing to enjoy everything we did today, and having given you a rather memorable lesson in responsibility at the same time, I think you’re ready for a bit of a night out on the town. I for one am going to be going out while wearing your diaper, under a dress of course. Now don’t you start to be embarrassed by something like that Sweetie Belle.” Rarity said as she saw her sister begin to grimace at Rarity’s intended choice of public clothing.

“Remember, the fewer things in life that embarrass you the more opportunity you will have.”

“Now in you’re case Sweetie Belle, I want you to be in something a bit more form fitting than a diaper.”

With that Rarity levitated a plain white package out from behind the sofa where she had obviously had it hidden for the whole afternoon just for this very moment and held it out in front of her sister.

“From me to you Sweetie Belle. I won’t have you meeting any of my associates or clients on your first real night out without wearing something I made specifically for your beautiful body.”

“Wow, really, Rarity! Thank you! Thank you!” The teen filly said standing up and hugging her diapered older sister.

“And you really mean it? We can go out together tonight? This is so awesome…even if you do insist on wearing my diaper.”

Rarity smiled and nodded her head in conformation as her younger sister carefully took the lid off her new gift. Inside was a short dress where the top was made of good quality super shiny and slick black pvc plastic. It had wide shoulder straps but no sleeves and came down to the front of Sweetie Belle’s hips, the skirt part of the dress was very short, only just reaching the base of her tail and made of a thick transparent clear plastic that made a nice rippling sound when handled. This transparency allowed anypony to see through to her cutiemark and also to the included tight form-fitting shiny black pvc thong, a thong like the dress, that Rarity had custom made to not only fit her younger sister’s beautiful thighs and butt, but also to tightly wedge itself into her pussy thereby enhancing the overall stimulation of wearing the dress. While ponies typically went about their daily lives wearing nothing, and it was also typical to keep one’s tail down to prevent making more of a display of oneself than intended, wearing clothing was usually taken as something either for a very formal setting or for the purpose of enhancing one’s sexuality. In the case of Sweetie Belle’s new dress, the intent was very clear and the transparent plastic showing the tight thong underneath would erase all doubt. Besides, the thong forced Sweetie Belle to keep her tail raised to stay more comfortable, which only added to the subtle yet unmistakably erotic nature of her outfit. Almost as an afterthought a plain black pvc choker was also included in the box.

Sweetie Belle’s eyes began to tear up as she looked from the dress to her sister and then back again. Not only would this dress and thong make her look unbelievably hot but she could wear it for Applebloom and Scootaloo and perhaps get to have a good threesome again like they used to. A gift like this required a proper thank you and so, box held up in her magic, Sweetie Belle darted forward and kissed her beloved older sister hard on the lips.

As their tongues wrestled together, sliding into and out of each other’s mouths. Rarity knew that she had made all the right decisions and that now she was ready to share her precious little teen sister with the world.

Ch 2: Friendly Interactions, or, Love in the City

Author's Note

It took wayyyyy to long to make real progress on this story again. I apologize to my readers for not posting anything new in months. But, Faust! my life can be busy. Anyway, worry not! I will be posting even more new stuff over the coming days and weeks, You won't have to wait months more for it.

Ch 2: Friendly Interactions, or, Love in the City

For anypony who had any intention of publicly enjoying their fetishes, even subtly, confidence is a critical trait and its usefulness cannot be overstated. This, Rarity believed wholeheartedly. Having said that though, confidence is not an excuse for taking unnecessary risks or engaging in behaviors that might have unduly unpleasant consequences for a pony’s social standing. This is why she had made two decisions before she and her little sister had left her penthouse before their night on the town. The first had been to get Sweetie Belle to wear a very cute pair of light blue denim short shorts over her new pvc plastic thong and under the transparent plastic of the skirt. The shorts had no back pockets and fitted themselves to her round little butt amazingly well. Paradoxically while revealing less than the thong alone, they somehow managed to make the twelve-year-old mare even more enticing. Rather like a Christmas present with two layers of wrapping. It had been a good fashion decision, the only kind Rarity made anymore these days. Usually.

The second decision was to forego any sort of dress of her own as originally planned and instead put back on the skin tight black pvc plastic bodysuit she had begun the afternoon in. The advantages to this were several. Not only did it look and feel great to walk around in as she strolled down the twisting avenues with the soft warm light from street lanterns and open-till-late establishments spilling over the smooth cobbles and causing reflections to dance across the shiny plastic as she strolled by, but it made her thick diaper visible to everyone in a way that revealed no details about it. Even more importantly the material of the bodysuit went quite a way toward containing the smell. Thus she could be known by thoes who understood what they were seeing as a diaper wearing mare but only the ponies she knew the best would ever get a chance to see inside the bodysuit and know the full extent of her perversion.

An additional benefit was that the tightness of the garment kept the big bulky diaper and its wonderfully disgusting contents constantly pressed firmly against all the important areas inside it. If she had been so inclined Rarity could probably have made herself cum simply by galloping. It felt that good. Though the diaper was so well made that despite now showing a very visible light brownish stain all the way from right under her tail to almost the top of the front it would not have sagged much even without the bodysuit. As it was the diaper could hold its shape indefinitely under the tight pvc.

So this was the state of the two mares as they confidently strode down the narrow shopping street now a block from the ornate stone building whose top two penthouse floors had been witness to all manner of sexual misadventures.

“So, how are you feeling Sweetie?” Rarity asked, deciding she had enough of the attempted small talk and awkward silences she had endured since leaving home. It was time to get the filly a bit more confidant in herself. They turned a corner onto an even smaller side street angling in the general direction of Canterlot Castle itself providing a good opportunity for renewed conversation.

“Uh, I feel nice- um fine, I guess.” Sweetie said still looking around a bit nervously.

“Come now dear, that's not really an answer and you know it. What exactly are you feeling? I know it will make you feel good talking about it. Besides, not many ponies are going to hear you, and the ones who do will probably enjoy what you have to say considering the time and the district we are approaching…”

“You feel sexy don’t you.” Rarity added after a pause, and watched as Sweetie Belle started slightly at the blunt remark.

“How do you do it?” Sweetie Belle said looking up and directly at her big sister for the first time since they had begun walking.

“How do you just go about like this and not feel embarrassed? I mean, yah, ok, you’re right I do feel sexy, I love this outfit! And it makes me, um, well, it feels good between my legs and… and the plastic of the skirt feels good on my fur. But it’s still embarrassing -and I’m not even wearing a diaper.”

“Well, let me say this Sweetie dear, if you didn’t feel a bit of embarrassment about your situation I’d be a little worried. We both know you’re not new to intimacy, but those experiences have only ever been in private with ponies that you know very, very well. Being out in public and being ‘on display’ so to speak is another matter entirely.” Rarity replied, keeping an eye on Sweetie Belle’s dubious expression.

“Keep in mind that I have been doing this kind of thing since I was even younger than you, and all that experience builds a lot of confidence. You can’t be expected to be as sure of yourself as I am on your first night ‘out on the town’. I certainly wasn’t at your age.” Rarity continued.

“Simply remind yourself how good you feel and how happy that pleasure makes you. That enjoyment will ultimately overcome any self-doubt or embarrassment you may have. It’s hard for anypony to make fun of you when you are so obviously enjoying yourself after all!”

“So you’re saying I should just enjoy being myself and everything else will work out?” Sweetie Belle inquired.

“Well, I guess I am, aren't I.” Rarity replied. ‘Wisdom from the mouth of babes…’ she thought.

Seeing her little sister perk up at this confirmation allowed Rarity to relax again, the last thing she wanted was to have Sweetie Belle not enjoy herself on this special night. Rarity hadn’t picked this night specifically, but she was glad it had turned out the way it did. Even though it was still early October the nights were beginning to cool down up here in the mountains. Two thousand meters below them in the Celestial Valley, Ponyville would still be comfortably warm and the trees wouldn’t start to turn for weeks yet. Here though, the aspens were beginning to transform into their characteristic brilliant yellow and the maples were showing hints of fiery oranges and reds. None of this was apparent in the dark and dimly lit, but blessedly clean, alleyway they were winding their way through, but what was becoming visible however, were the occasional decorative pumpkin or gourd collection set out in anticipation of Nightmare Night. Instead of being creepy though, the occasional warm window light and the old stone shops and houses packed so close together made for a very cozy atmosphere in Rarity’s opinion.

Though of course it wasn’t so much the delightfully rustic urban surroundings that had Rarity in such high spirits. The warmth of the slippery mess coating the inside of the diaper currently residing happily between her legs was engendering a second more specific source of heat. That, and watching her little sister’s round butt and slim legs as she walked alongside made for quite the distraction. If there had been any obstacle present in the middle of the street just then Rarity probably would have smacked right into it. She was that distracted.

Fortunately for the both of them, she was so familiar with their destination that her ability to find it was nearly instinctual and it took little to no couscous thought to successfully arrive without incident. The building Rarity led her little sister to was not particularly remarkable, at least by the standards of the neighborhood it was in. Most other districts of the capital, perched at various levels along the eastern side of the Celestial Valley, would have considered the seven story rough cut marble and heat-hardened oak timber structure to be ostentatious and imposing. Here however, only a block and a half from the outermost walls of Canterlot Castle itself where the buildings became ever taller, more expensive, and in some cases quite historic, this particular structure fit right in.

If an enterprising pony were to go to the bother of looking up the building permits, structural application contracts, or even the city residency listings for the old and ornate edifice they would find it to be defined as a residential structure with each floor, besides the ground floor, which was taken over by a collection of high end retailers, laid out as one large, single apartment. Each floor occupied by either some wealthy merchant or various aristocratic family member -the type who wouldn't balk at the ten million bit per unit asking price. All in all, not so different from the building Rarity herself lived in. Though her place had merely cost half of what these flats supposedly went for due to the greater physical distance from the Castle. But Rarity was in no way envious of the residents of this tower or of their posh apartments, because in reality neither actually existed.

The idea had originally been Celestia’s. Whether or not this revelation proved shocking said much about how well a pony actually knew the princess in question.

Rarity had never risked prying into the original legal details too heavily but from what she had uncovered, she knew that around eight hundred years ago, near the beginning of an era of increased population growth and civic expansion that would ultimately lead to the founding of other relatively nearby communities such as Ponyville, there was also the start of an overall decrease in cultural prohibitions on sexual activity in part brought about by Celestia herself beginning to publically display a more liberal attitude, a sign that she was recovering emotionally from the admittedly temporary, yet still long term loss of Luna. This upturn in the number of ponies finding new ways to pleasure themselves and others, inevitably resulted in a dramatic increase in the number of brothels popping up in and around the capitol like so many woodland mushrooms. While the idea of sex for money itself didn't bother Celestia too much, the ponies who came to control the business did, and very much so at that. A new breed of pimps and unscrupulous brothel managers began to acquire money and influence at an alarming rate while at the same time making life increasingly worse for the ponies under their employment. Celestia knew that if she tried to shut them all down she might have temporary success, but sure as shit falls downhill new managers would creep in to fill the gaps and the only thing she would accomplish would be to drive the whole industry underground, and in the process make the lives of the poor mares involved even worse.

So, in an excellently played and completely unexpected move, Princess Celesta pulled off one of the finest instances of ‘If you can’t beat em’, join em’. That Rarity had ever heard of. Instead of shutting down the brothels she quietly took them over, using her political astuteness, myriad of contacts, and vast wealth, she bought buildings, payed off district managers, legalized new forms of business practices, and organized an iron-clad hierarchy of new loyal, honest, and most importantly, caring managers for every brothel in the whole of Canterlot. All of them mares. After all, it was now illegal for any male pony to operate a business that employed female sexual workers. From the point of view of the bewildered and suddenly disenfranchised stallions who had just the day before been making millions with the sexual organs of other ponies, the entire industry had simply vanished from reality as a business opportunity. If they tried to complain, nopony would listen as there was little moral or legal sympathy to go around. If they tried to set up an illegitimate business, nopony would work for them because they could make more money in better working conditions while remaining legally employed having sex under the watchful and caring gaze of Celestia herself. Effectively they were stonewalled no matter what direction they turned in. And as their monetary gains were accumulated from what was for them now an illegal practice they found to their horror that all their business assets and bank accounts had been possessed by the government and the funds and material goods redistributed to the mares who had been taken advantage of, to a variety of charities, or in the case of fancy furnishings, to line the halls and decorate the rooms of the castle and surrounding government buildings. By the end of the week Princess Celestia had become the Madame of the largest and most pleasant to work for sex industry in Equestria’s history. But for the average pony trotting along any one of the smooth cobble streets of Canterlot, not a clue of any of it was to be had.

As so it was, 789 years later, Rarity had gone to the Ministry of Public Welfare office and after a brief interview, had signed her name on a nondescript roll of parchment officially noting her as a public health worker in the direct employ of the City of Canterlot.

Of course, Rarity mused, as she led her little sister down a narrow street and up to a small door painted a deep blue located on the side of the grand structure, that original job would never have payed anything like what her present lifestyle required. But being a leading fashion designer and getting to know (and pleasure) the princesses personally resulted in a not insignificant income.

Pausing at the door Rarity turned to Sweetie Belle.

“By any chance do you know what this building is? Why I’ve brought you here?” Rarity asked.

“Uh, not really… is it a club or something that you like?”

“Hehe, well in a way I suppose your right, but not quite. You’ll see.” Rarity replied as her horn glowed faintly in the darkness of the alleyway, lifting a large brass knocker bolted to the middle of the door.

Rarity privately enjoyed her sister’s slight confusion at how she knocked on the door precisely once and then waited patiently a few seconds before the thick door slowly swung inwards silently with nopony visible on the other side. All very dramatic she thought. Typical of the ponies who had originally set this place up so long ago.

“Come on then dear, in we go!” Rarity said, smiling back at Sweetie Belle who was staring down the dim corridor, lit only by a few deep red light bulbs attached at regular intervals along the walls.”

Rarity had to admit, she didn’t remember it looking quite so spooky the last time she had visited. Perhaps they were toying around with another Nightmare Night theme. Wouldn’t be the first time, she mused.

“No need to be afraid darling, believe me, this is actually one of the safest places you can find in the whole city. After all it’s not unusual for one of the princesses to come here.” Rarity said watching Sweetie Belle’s face change from a dubious expression to one of hope and curiosity at the mention of an Alicorn.

“You never know, one of them might be here tonight.” She continued.

That seemed to do it, with renewed confidence Sweetie bounced up the two steps leading to the door and came in alongside her sister.

It wasn’t long after Celestia’s private coup in the world of physical delights, that she realized that having the Castle itself being used as the headquarters of every brothel within the kingdom might lead to some awkward difficulties. No, that wouldn’t do. Not at all. Which is why, under the pretext of building a new seven story condominium tower right next to the castle for the ultra-rich, the Highgarden real estate company, secretly owned by the Crown, commenced construction of Celestia’s new Sex Workers of Equestria headquarters building. A name that would only ever be printed once, on one scroll, and then sealed away permanently. Every other pony who ever saw it would have no idea what it was ever called or even what its official address was.

It wasn’t until after meeting a certain violet unicorn that she was privately informed by Celestia of the building’s existence and that she might well find herself a highly respected position there if she were ever to pay a visit.

The very building that she was now leading her little sister deeper into.

Rarity did her best to remain silent as she trotted down the hallway, sister in tow, towards one of the main stairways that would lead her all the way to the top floor. The prospect of climbing fourteen flights of stairs was always a bit frustrating to her, but the building had been built well before the mechanical elevator had been invented and as such including one would have required quite the remodeling effort. Something not looked favorably upon by thoes who wished to limit the number of ponies who knew the true purpose of the facilities contained within as much as possible.

However, Rarity admitted to herself, there were two benefits to the stairs. The first being simple good exercise. The second was that the act of climbing stairs in her messy diaper would prove...enjoyable. Especially as her cock had begun to harden again at the prospect of arriving at her destination.

So, up she went, feeling her hardening dick squishing further into the warm semi-liquid gooey poop spread around inside her diaper. The tight shiny catsuit making sure the diaper was held tightly in place. The same slimy mixture was being spread liberally over her pussy lips at the same time making it difficult to not moan the farther she climbed. All the while the more rational part of her mind was enjoying the idea that her little sister was currently able to enjoy the sight of her diapered backside as they ascended.

They encountered their first pony on the landing between the fourth and fifth floor. She was a unicorn, still the most common race to be found in Canterlot, and seemed to be angling for a mild goth look. Her light greyish blue coat and dark navy blue mane, almost a very deep purple, certainly helped that look along. She wore an extremely thin purple thong and socks on all four legs that matched her skimpy choice of underwear in color if not fabric type. A black leather choker and black eye liner completed the simple yet effective outfit. Rarity had seen the mare once or twice before, though she had been a member of The Organization for only a year or two. If Rarity recalled correctly she had a sister her own age.

“Hello, Moonlight.” Rarity said softly with a quick smile as she and Sweetie went past, praying to Faust the whole time that she had remembered the pony’s name properly. Perhaps in keeping with the moody goth character the mare didn’t reply with words but simply speared Sweetie Belle with a predatory grin that would have done a Griffon proud. Sweetie Belle for her part flinched slightly while trying not to do a double take.

Were those teeth…sharpened?

Sweetie hurried off after her Sister with the fur along her back standing on end.

A minute later Rarity, now slightly winded, arrived on a wide landing at the top of the stairs in front of a wide set of double doors made from some hard wood of great age. Centuries of polishing had resulted in a deep gleam off the smoothed surfaces. The doors themselves were inlaid with finely detailed reliefs that when properly examined showed a multitude of ponies, most of them mares, engaged in a great variety of sexual acts.

Finally, Rarity turned to Sweetie Belle and spoke to her.

“What you are about to see may surprise you to a greater or lesser extent depending on who has decided to drop by this evening. But I rather think you will not be too shocked seeing as we have the relationship that we do. And just remember everypony will be quite happy to see you here, I assure you.”

Rarity was pleased with her sister, despite feeling obvious trepidation she was remaining calm and quiet. Well, quiet at least. Turning back to face the doors she channeled energy into her horn and lowered her head until the tip was aligned with a hole in the door’s lock conveniently just wide enough to accept it. As soon as the magic contained within the lock was satisfied that it recognized the magical field being inserted belonged to a pony it knew and trusted, a couple of dull thuds emanated from within the door itself as the locking mechanisms disengaged.

The heavy doors swung slowly inwards to reveal…a small vestibule.

Sweetie Belle silently puffed out her cheeks in minor exasperation behind her older sister at the anticlimax but quickly came forward as Rarity ushered her in to the small space while the outer doors began to swing shut. As soon as they had the lighting of the vestibule changed from the dim red that had been all pervasive in every other part of the building they had come through so far to a much more comforting warm yellow-orange glow. Only then did the plain inner doors swing outward without Rarity having to do anything at all.

She immediately knew they were in luck.

More ponies than she had been expecting occupied the room. Her gaze was instantly drawn to the centerpiece of the action. Right in the middle of all the expensive oak paneling and trim and the high backed furniture upholstered in what she dearly hoped was fake red leather was Princess Cadance clad only in a pvc bodysuit not unlike the one Rarity had on but colored a light pink. Cadance was hard at work fucking Twilight Sparkle with long powerful thrusts of her glistening cock, whom she had bent over what looked like some sort of cheap inflatable bean bag like object made of soft bright green material utterly at odds with the decor of the large yet cozy feeling room. There was a thick and heavily wet disposable diaper laying open on the floor between Twilight’s rear legs. It was easy enough to surmise that it had been doing its job as Twilight’s personal bathroom right up until Cadance had decided that what lay buried under all that warm wet padding was more important.

Rarity had seen enough alicorn sex by now that the sight, as beautiful as it was, could no longer hold her transfixed if she didn't wish to be. And though the ongoing spectacle of raw Princess into Princess action was certainly hard to resist, there was another pony among the dozen odd others in the room, some she immediately recognized, some not as easily, that caught and very much so did hold her attention.

Fluttershy was sitting slumped down in one of the oversized high backed chairs in the back left corner of the room not far from the large marble fireplace and the merrily flickering fire therein. She had on only one thing, a very thick and very wet disposable diaper. She was staring at the two rutting mares in the middle of the room with a forehoof slowly rubbing circles around the front of her diaper and a somewhat glazed over expression on her face. If she had noticed Rarity and her sister’s arrival she hadn’t made any sign of it. Watching the yellow pegasus enjoy herself in such a manner with a dozen other ponies around her said much about how friendly and accepting of a place this was, assuming you had the right connections to know about its existence at all.

Rarity knew that this was not the first time Fluttershy had been here because she had been the one to bring the shy pony here in the first place a few years back. But this was the first Rarity had seen of Fluttershy coming here on her own without Rarity leading the way. She smiled at herself, seeing that Fluttershy was obviously working on independently expressing her sexuality. Always a good thing for a mare to work at.

Despite her concentration of Fluttershy, Rarity was distracted by a scream and a groan as Cadance came hard deep inside Twilight. The smaller alicorn shuddered as pulses of hot cum splashed into her and Cadance strained hard the whole time burying herself into her partner until nothing of that glorious dick could be seen. Rarity wasn’t sure she could take Cadance herself. That pony was…large. Twilight could, only just, and she was physically a bit larger than Rarity.

A spray of clear mare cum erupted out around the base of Cadance’s shaft, while the last of Cadance’s own was released, as Twilight came. Cadance slowly withdrew herself the tight muscular passage allowing the full length of her glistening shaft to be revealed to Rarity. A thin strand of something clear and sticky bridged the gap between the stiff head and slick pussy lips in front of it for a second or two before breaking into droplets. Twilight slid sideways off the green cushion to plop unceremoniously onto the floor breathing heavily with a look of bliss on her eyes. Some of the surrounding audience even clapped a bit. Rarity had to smile at that, the Princess of Love was a force to be reckoned with when she was horny. Cadance bent low and whispered something unintelligible into Twilight’s ear, which twitched, and made Twilight look up at Cadance and quickly lick her nose. Twilight grinned at Cadance’s startled expression. Rarity for her part had to look away for a bit while stifling a laugh.

When she looked back, Cadance, horn aglow, was busily taping Twilight back up in the diaper she had been wearing before things had gone all hot and heavy. Rarity was not particularly surprised that she instantly recognized the brand as it was from her luxury Padded Fillies line of teen and adult disposable diapers. The one Twilight had on was white down the center with the leg guards and sides colored blue, green, and pink in the style of Princess Celestia’s mane. Or rather, it would have been white but for the obvious heavy wettings the diaper had soaked up. Rarity was pleased to see that despite swelling to nearly twice its original thickness by all the warm urine, its padding was holding together perfectly and the tapes had been pulled quiet tight with no noticeable sagging. Even after having been taken off at least once. A diaper worthy of an Alicorn, Rarity thought.

And Twilight did look spectacular in it. The soaked bulk was gracefully hugging that toned butt and athletic body. Twilight was in amazing shape for a pony so nerdy. Rarity chided herself for the stereotype comparison, but really, it was sometimes difficult to associate this pony with the same one who once lectured to her for half an hour on the implications behind quantum to classical information decoherence before realizing her audience of one had no idea what was being said.

“So? What did you think?”

Rarity jumped at the sudden and unexpected intrusion into her reminiscence.

“You looked like you were enjoying the show there, though of course so was everypony else…” Cadance continued with an almost private smirk.

“Oh! You were amazing, and so was Twilight at that! It’s not just anypony who can impress me that way. Ah, I wasn’t aware you were in town so to speak, you seem to be here more often than you used to.” Rarity said with a hint of inquiry in her voice.

“Hm, yes, well the Empire is so much more stable than it used to be, and Shining does so love to play at being a prince…Really though, the country practically runs itself so far as day to day concerns go. I know I’m the ruler and all, but my role is more figurehead and ambassador now than it was before.”

“Did you know we’ve gotten so much better at learning how to grow Chrystal structures, thanks in part to Twily there? The Chrystal Palace isn’t even the tallest structure in the city anymore! Just think where we’ll be in a few more decades!”

Rarity had to smile at that, even in a place like this, even just after having hot sex, Cadance’s enthusiasm for the small but swiftly growing nation she ruled over shown through like the sun.
“Really! I had no idea! And it’s only been a year since I visited. I really should do something about that. It’s just there’s so much to do here every day, time just seems to slip by. Well, you know how it is.” Rarity said looking a little embarrassed.

“Oh, don't worry about it, I’ll arrange a trip soon for the both of us then. We’ll work out something, it’s as much my fault for not having any plans myself. But, for the moment…I’m more interested in what you’re wearing, Rarity. Cadance said changing the subject in a way Rarity was half expecting.

“You know… about that, what we’ll get into might not be for everypony here, perhaps a private room would be better.”

It wasn’t that Rarity was trying to hide her diaper from all the other ponies, it was more a combination of understanding that opening up her diaper in its current state might not be agreeable to everyone in the room and also by hiding herself away with only a few mares she enhanced her image as a more exclusive pony who didn’t just put on shows for free to everyone. Not even here. Let the other ponies use their imaginations! She though, that way they would be even more eager to see her perform in the future.

“Oh, that nasty huh? I thought I smelled something coming from over here…” Cadance said nearly giggling.

“One of the side rooms should do nicely then!” Cadance said turning towards a door on the right side of the lounge.

“Ah, Cadance, there was actually somepony I’d like you to see.” Rarity had to say quickly before Cadance rushed off.

“Who is that, is it Sweetie Belle? Did she come here with you?”

“Yes, actually! I know you two have met before but it’s been quite a while. I thought, well, she’s twelve now you see, and quite old enough to take part in certain activities now, so…” Rarity trailed off.

Cadance smiled brightly at Rarity. “Well of course! Do you want her to watch us then?” Cadance asked with a grin.

“Hehe…well more than watch actually.”

“Oh really…that will be fun then. Does she have much experience?” Cadance asked.

“From me yes, and probably from Applebloom- her marefriend, but not any other ponies that I’m aware of.”

“Thank you for bringing her here then! I consider it part of my duties as Princess of Love to help instruct fillies in the ways of pleasure. So, I have to ask then, you, and her, and…messy diapers? Cadance asked hopefully.

Rarity had the presence of mind to seem slightly sheepish. “Yes, on several occasions. Actually just a few hours ago in fact.” Might as well be honest Rarity thought.

Smiling while raising an eyebrow Cadance turned to regard the filly, who Rarity now saw had taken it upon herself to go over to talk to Fluttershy, who seemed slightly embarrassed to be seen in such a place by a filly from her own town. Though Rarity suspected that thoes feelings were superseded by seeing a filly from her own town in this place to begin with.

Sweetie Belle for her part seemed to be chatting away quite contentedly, apparently happy with being able to find a familiar face in this new environment. A few of the other mares were eyeing her quite openly. Obviously considering what fun could be had with a sexy filly in a sexy outfit. Rarity was privately smug that Sweetie Belles clothes were sexier than the majority of the other mares.

The two of them trotted over to the corner where Fluttershy had now gotten up from the chair and was standing between it and the fireplace. Rarity had fun watching the procession of emotions running across the Pegasus’s face. First came surprise at the new attention from both ponies, then embarrassment and a quick backwards glance at her diaper, then a blush and an almost hopeful expression as her mind computed what was likely to occur over the next several minutes considering the place and the ponies involved.

“Fluttershy! Darling, I’m so glad to find you here! I would’ve come straight over but I was rather distracted by the activities on display you see.” Rarity said in as much gentile happiness as she could convey as she gave the yellow pony a hug and a quick kiss on the cheek.

“Oh, Rarity, I’m glad too, it’s so nice to be here with friends…I don’t know if I would have come myself if I hadn’t known Twilight would be dropping by this evening. If you don’t mind my saying so you, um, look very nice in your outfit. I assume there is a diaper under there as well? Fluttershy said glancing quickly at Rarity’s flank.

“Why thank you! And yes, I am diapered, how could I not be with such promises of fun to be had on a night like this. If I may say so, your own diapers look fabulous on you! They fit you perfectly and well, the wetness makes the diaper go well with your coat color, its practically a fashion statement in of itself!”

“Goodness! Um, if you say so Rarity.” Fluttershy said blushing, but looking quietly pleased with herself.

“I uh, do love this diaper, it feels so, so very good on me. And it’s nice not having to go looking for a bathroom all alone in a building like this. Thoes hallways…” Fluttershy said with a slight shudder. Rarity smiled at her friend, Fluttershy would use that as an excuse to wear a diaper. Though to be fair, perhaps in her case it wasn’t always so much of an excuse.

“So Cadance and I, and perhaps Sweetie here are going to take a little trip to the side parlor for a bit more fun and we were wondering if you might just be interested in watching or even… maybe getting involved? After all, you did seem to be enjoying that diaper earlier when we came in.” Rarity couldn’t help herself from adding.

Fluttershy, looking embarrassed while rubbing one foreleg against the other did manage to nod vigorously in the affirmative.

“Oh good that makes three then, by the way where did Twilight go off to? She was here just a minute ago.” Rarity asked, looking around.

“I think she went back to the castle,” Cadance replied, “she mentioned something about having some further study project to attend to there.”

Rarity had to work hard to not roll her eyes at that, though…on second thought, Twilight was just sneaky enough that maybe this time “study project” didn’t exactly mean what it normally would have. Now she was having to work hard at not smiling while contemplating exactly what kind of “project” she was “studying”. Rarity considered that perhaps a late night trip over to the castle may well be in order, assuming everything went well here first. After all, she could hardly allow the Princess of Friendship, and her good friend, to get away with those sorts of clandestine activities without her at least knowing something about it. But first things first, there were ponies counting on her in the here and now and it would take her full concentration to not disappoint them. Twilight and her nocturnal activities would just have to wait.

“So, Rarity, is this sexy little filly standing here Sweetie Belle? She really is something!” Cadance said smiling at the filly.

Rarity had to roll her eyes at herself, how could she have become so distracted by Fluttershy that she had forgotten to introduce her own little sister. ‘For shame’ she silently chided herself.

“Goodness yes, Sweetie Belle? This is Princess Cadance, you remember meeting her a few years back don’t you? If nothing else, I know you were at the wedding ceremony.” What a lot of overly politicized bullocks that was. Rarity added to herself.

“Oh yes, of course I remember, you were so beautiful! I mean, you still are of course!” Sweetie Belle added hastily, blushing, and remembering enough formality to bow slightly.

Rarity had to wonder if formality had any meaning left in a place like this.

“Why thank you, Sweetie Belle. I think you are beautiful too. In fact, I think you’re rather hot. May I kiss you?” Cadance asked.

Rarity was amused by watching her little sister’s mind desperately hurrying to catch up with this sudden intensification to the conversation.

“I, uh…yes! Um, please?” Sweetie Belle managed to squeak out. Cadance laughed softly and lowered her head down and immediately locked her lips with the filly. It hadn’t taken but two seconds before the ponies were making rather erotic sounds as their tongues fought for dominance. Cadance soon followed up by pressing a hoof under Sweetie Belle’s skirt and onto her soft round butt. Just as the filly began to moan, Cadance broke off the kiss and pulled back her leg.

“So then, weren't we going to have a bit of fun with whatever it is Rarity is wearing under that hot outfit she has on?” Cadance asked directly to Sweetie Belle.

“Perhaps we will continue our little session afterwards?” She continued, still addressing the filly.

Wide eyed in admiration all the star-struck filly could do was nod.

Interlude, or, Love in the Castle

Twilight Sparkle closed her eyes and sighed quietly in resignation. The diagram in the thick, dusty, and inordinately old book, now faded after so many years, simply refused to make sense. She understood what the diagram was, it’s many nested loops and small dots with labels written in a truly ancient unicorn script was a representation of a solar system. The large loops were the orbits of the stars about each other and the smaller ones in turn represented the orbits of various planets. This of course was the problem, this congregation of astronomical objects the book was showing her was oddly similar to ones she had seen before. It was often depicted as a diagram of ancient Equestria before the princesses had control over the motions of the sun and the moon, both of which went around Equestria. Or at least Twilight had never given serious consideration that it could presently be otherwise, who would? Perhaps the stars in this ancient system were ones also seen in the night sky? If so, nopony had ever found a trace of them, if they had, her father would have told her, being one of the royal astronomers. He would surely have at least known about the knowledge of such an interesting group of stars and shared that information with her. She always did like to be kept up to date on all the latest advances in astronomy. Perhaps the diagram was simply ancient fiction, dreamed up by some bored unicorn scholar in his castle’s archive. But no, the diagram’s caption noted that even the original scroll it had been copied from for the sake of this book had itself noted that the diagram’s age was unknown and presumed to be quite old, and that the original labels for the planets and stars were from a language not known even then, and that scroll was now well over six thousand years old. So fact? Fiction? Presumably impossible to tell now, simply too much time had passed. And of course, the original scroll was the oldest copy of the system diagram ever found. The loss of even older vital information irked the lavender alicorn. Yes, Celestia had been quite studious about keeping the history of Equestria very well documented and archived, but there was nothing to be done about knowledge lost from so much longer ago. The history of pony civilizations extended back through time far before the Three Tribes Era, though what little of that was left was now nothing but cryptic, crumbling ruins dotted here and there amongst the mountains.

She turned the page over in frustration.

Anyway, it was too late at night for this problem now, and she was too comfortable to permit a minor annoyance such as this to ruin her overall good mood. Earlier that evening, she had put her signature to a few final documents in the stately office room she kept in Canterlot Castle itself, taken her shower where she had been vigorously cleaned all over by Princess Luna, who was herself preparing for night court, with blueberry scented shampoo and a curiously large loofah, then Cadance, having come down south for a visit from the Empire earlier in the week, had taped her up tightly in one of the thick disposable diapers made for her by Rarity. Its slick light suspiciously Celestia-colored plastic surface always glistened so nicely by fire or moon light. Then, the two of them had made their way through the secret passage extending out from one of the castle’s many basement levels out to the Red House. The most prominent of the Equestrian government- i.e. Celestia- owned brothels. She had spent some time there with Cadance who of course couldn’t resist her in that hot, wet diaper for long. The slight soreness under her tail spoke of just how much fun they had had there.

Of course just as they were finishing another of her best friends had shown up plus her little sister. Under more mundane circumstances she definitely would have stayed to chat but she knew Cadance well enough that between Rarity, her sister, and the unbearably cute and sexy Fluttershy there would be quite an orgy going on in no time. Honestly, she was already feeling a bit tired after her fourth time that night being penetrated by the largest alicorn cock she could take. It was time to go back to the Castle for a rest. Besides, she wouldn’t be missing anything that she couldn’t experience at a later time. All she had to do was ask, and a diaper play session would be organized within the day. She just wanted some time with a good book. Old habits did indeed die hard.

That then had been the cherry on top of the whole evening. Just as her introverted side had desired, she chose yet another near forgotten tome out of the Castle’s Library and joined Celestia herself in the ruler’s private sitting room. A place to snuggle up to her mentor and read by the light from the flames in the wide stone hearth until she fell asleep, usually nestled under one of Celestia’s wings. The entire time taped up securely in the warm, soaked diaper she had now spent half the day wearing.

Therefore, it was even more annoying that this night’s book had included the system diagram and associated offending lack of context.

“Something the matter Twilight?” Celesta asked quietly as soon as the sigh, however unobtrusive, had escaped her lips.

“Huh? Oh, it’s nothing, just some missing information in this book.” Twilight said glancing up as her mentor gave her a slight knowing smile. After all, Celestia knew better than almost anypony how much Twilight hated things that were left incomplete.

“Well, if the content of that book is half as old as I think it is you’ll just have to get used to it, I’m afraid.” Celestia said. The smile had turned almost teasing.

“So I’m finding out.” Replied the smaller alicorn, with a hint of sarcasm leaking into her words.

After a soft chuckle and a quick kiss behind Twilight’s right ear Celestia laid her head back down on the large red velvet pillow before her and closed her eyes again, resuming the same position she had been maintaining prior to Twilight’s little unintended emotional interruption.

Twilight couldn’t help but stare just a bit longer at the snow white fur and ethereal flowing mane of the Alicorn snoozing contentedly by her side. The dimming firelight from across the well upholstered and wonderfully cozy chamber off to one side of Celestia’s formal bedroom gave her a bit of a golden aura.

How appropriate, Twilight mused to herself.

Twilight turned back to the book to begin an investigation of the ancient charts and artworks catalogued on the next page, and found after a few minutes of effort and failed attempts resulting in captions being read three times over without comprehension that she was indeed distracted.

It was no one single thing. Celestia, the angelic pony now apparently quite sound asleep beside her keeping her feeling snug and cozy, the dimming fire in the hearth making it harder to read the tiny words crammed onto the pages, the way the extra thick diaper felt around her, perhaps the fact she had to use the bathroom quite badly now.

Ah, yes, that was probably it she realized.

Twilight, or more specifically her diaper, had indeed been quite wet for a while already by this point. In fact, she had given the diaper a good soaking nearly the second Cadance had finished taping the thing around her slim waist. Which had been what? Nearly ten hours ago now? In her deep concentration on the book Twilight had rather forgotten all about the diaper and how nice it felt on her. However, that annoying diagram had broken the spell, and now, thanks to the diaper she couldn’t get back in her groove, so to speak.

The irony did not escape Twilight for the first time that the diapers she had started to wear, conveniently provided by the princess as a young filly, supposedly to prevent distracting things like bathroom breaks from interrupting her study time, now had rather the opposite effect. Maybe that had been the idea all along?

This time, keeping the sigh inside her head, Twilight carefully closed the book with a quick flare from her horn and pushed it aside. Perhaps tomorrow she would continue with this same one instead of picking out yet another volume from the seemingly endless archives. But either way, that was a decision for the next evening and right now she had other things to consider.

Twilight gave Celestia’s sleeping form a sideways glance, almost wishing the princess to be awake at this moment. Twilight admitted to herself that this was even more fun when being watched, but Celestia had watched, and enjoyed watching, and perhaps done a bit more than just watching, Twilight go in her diapers quite a number of times before. If she missed this one there would be tomorrow or the next day to do it all over again.

There was something so enticingly and enjoyably naughty about wearing one’s own bathroom and having no qualms against using it for that purpose, Twilight thought as she raised her tail slightly.

All it took was for her to release the hold she was keeping on her anus and a huge squishy mass practically exploded into the back of her diapers followed by a thick, soft flow of poop the consistency of wet mud; a bit too squishy to hold its own shape that then pressed into the first mass and forced it to push further out into her waiting diaper.

As the giant goopy load expanded out to fill the back of the diaper, Twilight did sigh out loud again. Truthfully, it was closer to a moan this time.

Just as the massive mess began to slowly flow downwards to cover her waiting pussy, Twilight raised her hips off the soft rug under her and released her bladder once again into the diaper. The hissing sound she made as her pee splattered into the already soaked padding was surprisingly loud in the otherwise nearly completely silent room about her. She could feel a renewed warmth spreading down from her pussy and then between her legs in a steady progression towards the front of her diaper. She loved the feeling, not only because of the hot pee being soaked into her fur that the diaper didn't capture, but because of the way the thick absorbent padding firmed up as it became saturated, making for a wonderful bulky feeling between her legs.

She had finished her second wetting just in the nick of time as she felt the thick mass of her poop flow down completely over her now quite excited pussy lips.

This was simply too stimulating, Twilight couldn’t just go to sleep now, no way, not with this diaper on. What a mess! She had surprised herself with the quantity of poop she had let out to fill her diaper.

As much as she desired to do so, Twilight decided to not immediately sit up and squish herself down and around in her mess. No, for a diaper like this she was going to need to need some ‘help’. There was no way she was going to let a diaper with this much potential just sit there all night without being actively enjoyed. Perhaps she could extract herself from her present situation and return to Princess Cadance? After all, that pony, more than anyone, knew what to do with a messy diaper. The only problem was getting to Cadance, who was no doubt still back at the Red House, having a great deal of fun. Twilight would know when she was finished, she was sure, because Cadance would certainly bring at least Rarity and Fluttershy back with her and when she did Twilight would once again be involved in something kinky. The only way Twilight could think to get there without any chance of being seen was to teleport, a dangerous proposition without being able to directly see one’s destination. An invisibility spell would do no good either. They could not function on castle grounds due to charms woven into the ancient stone structure itself for obvious security reasons. Maybe if she put on a dress over the-

A large white wing curved up and over Twilight, then curled onto her back and side, pulling her toward the wing’s owner and pressing her into the silky soft fur of Celestia’s side.

All the sudden Twilight’s planning became pointless.

Ch 3: Educational Interactions, or, Love in the Brothel

Author's Note

Not a long chapter, but rather fun to write!

Ch 3: Educational Interactions, or, Love in the Brothel

“So, Rarity, let’s see what you have on under this sexy outfit.” Cadance said running her hoof along Rarity’s side and then making circles over her diapered hips where her cutie mark was.

“Though I think we already know.” She added.

Sweetie Belle was watching what Cadance did more than paying attention to Rarity. After all, she already knew exactly what was under that black pvc bodysuit and she also had a pretty good idea as to what Rarity was planning. Cadance however, represented an altogether more interesting unknown. Fluttershy for her part went over to the small, yet equally ornate room’s only sofa and proceeded to slowly settle herself down on it, obviously enjoying the way her soaked diaper squished under her. It would seem she was content to watch for now. For most any other pony Rarity would have insisted that they join in the fun, but she had learned long ago the wisdom of not forcing Fluttershy into things any more quickly than she was willing to do so on her own. When Fluttershy wanted to join them, if she did, she would do it at her own pace.

“I’ll show you what I’ve got on under here if you show me what you have in store for me first.” Rarity said, letting Cadance know that she wasn’t the absolute boss of the situation.

By way of a reply Rarity watched the air around the tip of Cadance’s horn glow pink accompanied by the sound of a zipper from somewhere underneath the pink alicorn. Cadance turned a bit to the side and grinned down at Rarity.

“Well? What do you think, is she big enough for you?”

Rarity managed to not gulp audibly, that would have been just a bit too much of a trope for her peace of mind. But dear Celestia, it was big, and beautiful as well. About half again as long as her own, Rarity guessed. This skin looked slick and wonderfully smooth as the shaft bobbed about underneath Cadance as she turned slightly giving Rarity different views.

“I, uh, I’d very much like that inside me.” Rarity said, inwardly cringing at how much like a desperate filly she was coming across right now. And in front of Sweetie Belle no less. How embarrassing.

“Hehe, I don’t doubt it! But as I recall we had a deal. So may I please see what you have on under there? Cadance said batting her eyelashes in mock innocence.

“O- Of course, just a sec!” Now it was Rarity’s horn who’s turn it was to glow. But in her case she did more than just unzip the area around her crotch. With a bit more telekinetic application she was shrugging out of the shiny bodysuit she had arrived in. The air of the room felt nice and cool on her slightly sweaty fur now that the garment was off.

Cadance made happy sexy noises at finally seeing Rarity’s –originally Sweetie Belle’s- used diaper finally exposed.

And used it certainly was. Almost the entire surface of the slick plastic of the diaper from under her tail to the top of the front was stained a light brown, and the diaper bulged in only the way a truly soaked one could be. Rarity couldn’t be sure but it looked like Cadance’s shaft was even a bit more stiff than it had been just a minute earlier.

That was the point at which a pink hoof pressed into the front of her diaper reminding her of her own very hard cock. And how it was straining against the sloppy poop coated padding embracing it.

“Rarity, Rarity… what would ponies think if they saw what I’m seeing? A mare like you wearing something like this…” Cadance said shaking her head but grinning all the same. Truly you do live up to your reputation as one of the sexiest unicorns in the whole country. I’m proud to be your friend, Rarity.”

The sudden switchover to frank honesty in Cadance’s voice caught Rarity rather off guard.

“I think I’m the one who should be saying that, You’re the princess here after all…”

“Nonsense, anyone should be proud to be your friend.” Cadance said as she leaned in for a kiss.

The two of them locked their muzzles together, tongues fighting for dominance. Cadance’s mouth tasted faintly of… piss? Where had that come from? Rarity wondered. Twilight perhaps? Who knew what the two of them had been up to before she and her sister had shown up. Not that it mattered, Cadance would have tasted wonderful to Rarity just then, no matter what the flavor.

The whole time Cadance’s hoof had been sliding up and down the front of Rarity’s diaper, tracing the outline of her rock hard shaft underneath. She was having to interrupt the tongue wrestling match now to moan with increasing frequency.

“From the sound of things we need to progress to the next stage.” Cadance said, breaking off the kiss.

“Here, let’s give you something comfy to sit in.”

Rarity’s fleeting mental image of one of the plush chairs from the main lounge was swiftly flung away as Cadance lowered herself to the floor and rolled over presenting her underbelly and that long and thick hard shaft to the ceiling. The Princess of Love looked so hot laying there, upside down, mane and tail hair going everywhere. The skin tight pink pvc body suit she still had on added a subtle latex-fetish component to the whole ensemble, making Rarity stare helplessly transfixed. It wasn’t often that she felt so much the inferior in the arena of raw sexuality as this.

A ‘come-hither’ motion from one of Cadance’s hoofs broke the trance and Rarity approached, sensing, but not being quite sure what was expected of her.

Cadance’s other hoof lightly stroked her hard dick.

“Here have a seat, I think you’ll find it quite comfortable.” Cadance said looking meaningfully at her shaft.

Now knowing exactly what the princess had in mind Rarity carefully maneuvered herself so that she was standing with two sets of legs on either side of Cadance’s mid-section so that her diapered crotch was directly above Cadance’s own. Bending her back legs Rarity lowered her behind so that the front of her diaper came to rest directly on top of Cadance’s cock making a wet squelching sound as the full weight of Rarity’s body came down to rest on her diaper and the long shaft underneath it. The pressure also forced her own still diapered cock to press onto Cadance’s doubling the pleasure already coming from her dripping cunt.

Both she and Cadance moaned in unison at the force of the contact. Her diaper was thick and bulky enough that it seemed to envelop Cadance’s shaft. Like two smooth light brown lips gently parting around the length of the enlarged member.

Rarity dragged her upper body forward so that the front and crotch of her messy diaper slipped along Cadance’s length. The smooth warm plastic of the diaper made the princess whimper while Rarity shuddered.

“Mmmm, I bet you like my diaper even more now don't you, Cadance? Rarity asked as she continued to slide her diapered crotch up and down the Princesses’ cock. Rarity’s own felt like it was ready to burst.

“Oh, Rarity, just keep doing this, please!” Cadance said as she gripped Rarity with her forelegs right above Rarity’s hips along the top edge of the diaper.

“Oops! Hehe, I think I’m leaking on you, Cadance…” Rarity said, unable to stifle a giggle. Looking down Rarity watched as brown, foul-smelling fluid dribbled out from the leg holes of Rarity’s diaper and either smeared onto Cadance’s chest or onto the front of the diaper immediately getting spread onto Cadance’s member. The fluid made for a great lubricant, like oil but much kinkier, which allowed Rarity to slide the wet front of her diaper forward and back even faster. Cadance loved the feel and even the smell of the brown liquid dripping everywhere, it made her unbelievably horny. Playing with the bodily waste of another mare was one of the best experiences a pony could have.

“Uuuhhh…Rarity, I need more! Cadance whined.

“I don't think I can fuck you, but I can fuck your diaper, let me get inside it! Please!”

“Oh, don’t worry, you’ll get exactly that!” Rarity said as she decided that as good as her diaper felt on her now, it had a higher calling elsewhere.

“You just lay there and let Rarity do the work.” She winked playfully at Cadance.

With mildly erotic wiggling Rarity teasingly undid the tapes on her diaper one by one while Cadance looked on mildly surprised, she hadn’t expected Rarity to take off her diaper quite so early in the game. As the dripping diaper came free of Rarity’s hips she pulled her tail through and levitated the open diaper in front of Cadance. The inside was a sea of slick brown creamy poop, perfect for any playtime. Equally coated were Rarity’s own long bobbing shaft and pussy. Now fully exposed to the air she shivered in the most delightful way.

With care Rarity’s magic tugged Cadances cock fully upright while still levitating the diaper. With that done, she placed the inside of the sloppy diaper firmly against its length and wrapped it fully around the member, taping it in place. The diaper, taped lengthwise formed a thick tube a bit longer than Cadance’s shaft which was now fully encased at the center. Warm brown liquid began to seep out the bottom and over Cadance’s heavy balls and dripping pussy.

Despite looking a little ridiculous, Rarity knew from personal experience just how much pleasure the diaper was able to bring to Cadance in this way. It was like a fleshlight sex toy for a stallion but a hundred times better. A rock hard shaft wrapped up in a messy diaper was second only to a good poopy fuck.

With her magic, Rarity began to slide the rolled up diaper up and down Cadance’s length while gently squeezing in a rhythmic motion. This was a tequnique she had tried before only on herself on the rare occasion she had no play partner and the occasional stallion who payed well. The problem was that the only mares she was aware of who currently had both complete sets of genitalia were herself, Cadance, and Celestia. Luna, for her part, liked to remain fully female to better fit the feminine role in her relationship with Celesta. This resulted in a distinct lack of potential female partners who had a penis to experiment with. Though Rarity was hardly bothered by this, as a beautiful wet pussy was really all she needed to stay content.

Not to say, of course that she wasn’t currently enjoying herself immensely right now.

Cadance moaned a wriggled on the floor, breaths becoming gasps as Rarity slid the thick messy diaper up and down her shaft with slowly increasing speed and force, like she was pumping for oil.

“You know Cadance, I forgot to mention something important earlier. Would you like to know what that is?” Rarity asked with a sly smile.

“Mmmm…uuuhhh…I…w- what?” Cadance managed, squirming some more at the relentless pumping of the diaper along her shaft.

“You see, this diaper that you’re enjoying so much right now…well, its not actually mine… and neither is the slimy poop inside it you love so much. Yes, I was wearing it, but the pony who made all the mess in it was my sister Sweetie Belle. I just put it on after she took it off.”

Cadance’s eyes got a bit wider at that, she first stared past her thickly diapered shaft at the slick brown gunk coating everything between Rarity’s legs and the pussy and cock located there. Then she focused on the diaper wrapped around her dick that was making such lewd squishing noises as Rarity’s magic field slid it up and down. Finally, she let turned her head to the side where the previously ignored other pair of ponies were.

As they had become increasingly horny watching Cadance and Rarity at their expertise. Sweetie Belle had offered up her jeans shorts covered butt to Fluttershy who had pressed her soaked diapered crotch against it happily and began humping eagerly, her warm pussy lips pressing into the piss soaked padding covering them. Sweetie Belle for her part loved the feeling the smooth plastic bulk of a larger mare’s warm wet diaper being pressed up forcefully under the base of her tail. In addition to being incredibly hot, the feeling was oddly comforting. It just made herself feel good inside having a mare behind her who so obviously enjoyed who she was with.

This was the state of affairs that was present as Cadance looked over to see the filly who was actually responsible for the mess between Rarity’s legs but also the soft squishy scat currently coating her dick.

There was Sweetie Belle, eyes wide open and staring straight back at her, head to the floor and butt sticking up in the air. An oblivious Fluttershy rubbing and bumping her thick diaper against the filly’s butt for all she was worth.

Rarity knew what was going to happen soon now, and so chose that moment to double her speed and force with the diaper.

Cadance’s body surrendered.

“AAAAAHHHHHHHHHH!” Cadance screamed.

Her large heavy balls pumped hot cum into her rock-hard shaft that then propelled the sticky fluid out the tip with such force that most of it splattered onto the ceiling over two meters above her cock’s head.

And then she did the same thing again, and again.

Rarity was more than impressed. Not only was the force of Cadance’s ejaculation greater than anypony aside from Celestia herself, but this was barley a quarter of an hour after the Alicorn has just came hard into Twilight Sparkle. And on that topic, what must have it felt like for Twilight? To have that long shaft spray its thick load into her body with such force? No wonder she was looking to be fucked by Cadance at any opportunity. Rarity was actually a little envious, a feeling she wasn’t used to much anymore. Why did Cadance have to be just a bit too large for her? Perhaps she could convince Twilight to grow her own stallionhood, at least temporarily, so Rarity could have a taste of what it was like.

Rarity slid the rolled up diaper slowly off Cadance’s still hard cock making the alicorn convulse slightly. Her duty to the Princess done, Rarity was now insistent on having her own bit of pleasure. Cadance had unzipped her pvc bodysuit enough to let her balls and shaft free, and in doing so her tight anus was also exposed. Still laying upside down on the floor panting softly Cadance was so vulnerable looking and the exposed butt of an alicorn was not an opportunity Rarity could pass up. Besides, her own shaft was already coated in the best natural lubrication imaginable.

Lining her wide head and not insignificant shaft up with the puckered opening, Rarity eased herself into Cadance’s butt. It was wonderfully tight, but the slick poop coating her dick allowed her to slide in easily. Though only at first. After just a few centimeters in her head squished into a large soft load of poop filling the passageway it was trying to press into. The unexpected resistance made Rarity stop in surprise until she realized what she had encountered.

This knowledge only made here press harder.

As she forced her way into the thick poop, the pressure of her entry made the hot mass flow around her head and shaft, enveloping its full length in a squishy wet embrace. This was in fact the one thing equal to, or better than the diaper fuck she had just given Cadance. What luck! She would have to be sure to make the princess proud.

Without pulling out Rarity simply began moving her hips around in a circle while pumping a little, an excellent way of making the mass of poop surrounding her shaft to squish all about in different directions.

Rarity knew she wasn’t going to last long doing this but she no longer cared, after all, in the end neither had Cadance.

After a minute or two of more steady fucking, of just basking in the feeling of being balls deep in the soft stinky poop of an alicorn princess, Rarity began to feel the muscles in Cadance’s butt begin to contract with impressive force. ‘She’s going to the bathroom with me inside her!’ Rarity laughed to herself. Rarity decided that she wasn’t going to be so easy to expel.

Just as Cadance’s butt pushed on her shaft again, Rarity forced herself in even deeper, now feeling the poop flow around and past her length. The feeling was glorious. Almost immediately poop began to squish out around her hard cock and press into her wide balls as they were forced up against Cadance’s butt. The poop then began to half flow, half drop out onto the floor.

Having anal sex with a pony who was simultaneously pooping was simply too much for Rarity to take in her present state. With a yell almost the match of Cadance she erupted inside the princesses’ shapely butt, pumping thick wads of cum deep into the pony in front of her. The squishing and slapping sounds were hot enough to keep her going for a full minute more, just long enough for her to cum a second time as it happened.

Utterly exhausted, she let herself slip free from the loving embrace of her current partner’s rear and slumped back to sit on the floor.

As Rarity was trying to recover from her exertions Cadance rolled over and sat up.

“Well, we two certainly did enjoy ourselves didn't we? Cadance asked rhetorically.

“I apologize in advance if this disappoints you, but that’s not actually the first time a pony has done that to me with a dirty diaper.”

“It’s not?” Rarity asked, sounding more surprised than disappointed. And here she had thought she had been so creative.

“No…but it was the best job of it anypony has done, and it was the first time that that pony had done so with the dirty diaper of their little sister which they had secretly been wearing all along! That was special!”

Rarity knew she was blushing rather heavily under her fur.

Before being able to come up with an appropriate reply, Cadance made a meaningful gesture at the pile of soft brown poop on the floor between them. Some of it had been splattered around a bit from emerging while Rarity was cumming so forcefully.

“I would think that this is ultimately my fault, wouldn’t you agree Rarity? Cadance asked.

“As such, I think I should find something constructive to do with it. Now that the two of us have had their fun, I believe I have a job to do. As you were so kind as to bring Sweetie Belle here I imagine that you were hoping that your adorable little sister would be able to acquire something of an education tonight?” Cadance asked, already knowing what the answer would be.

“I well, uh, actually yes…” Rarity said, caught off guard by the unexpected frankness of Cadance’s assertion.

Cadance smiled.

With just a glimmer of her magical field Cadance scooped out a little from the slowly spreading mound of poop in front of her and liberally smeared it over her lips like some little foal who had gotten into their mother’s makeup kit and had discovered the lipstick.

“Sweetie Belle…would you come over here please?” Cadance said without looking away from Rarity.

A shuffling ensued as Sweetie Belle removed herself apologetically from underneath Fluttershy who had apparently still been enjoying humping the little filly’s butt with her soaked diaper. And despite a somewhat apprehensive expression she trotted over without hesitation. Rarity was proud of that confidence. It would server her sister well in the future she knew.

As soon as Sweetie Belle had stopped in front of the skinny pink alicorn Cadance leaned forward, poop smeared lips on display.

“Make out with me.” Cadance said.

Standing behind her little sister, Rarity couldn’t see what Sweetie Belle’s expression was or if she had whispered anything, but whatever exchange had gone on made Cadance grin, an action which smeared brown liquid on thoes otherwise glittering white teeth Rarity noted, and locked lips with Sweetie Belle. Both of them were soon moaning softly through the wet squishing sounds their mouths were making.

Rarity became stiff so quickly she surprised herself.

Suddenly, Cadance broke off the kiss.

“Goodness Rarity, and you too Fluttershy, this lesson is meant to be private! I thought you knew!” Cadance said in a shocked sounding voice, despite grinning like a cat.

“Huh? But…?” Rarity started.

“No butts!” Cadance retorted like a stern parent.

“I would suggest that you clean yourself up, then get into a fresh diaper.” Said Cadance waving a hoof in Rarity’s direction.

“And Fluttershy?”

“Y-yes?” Asked the pegasus, not quite courageous enough to meet the princess in the eye.

“How is your diaper doing? Have you messed it yet?”

“No, um, not yet…just very wet.” Fluttershy replied, absently pawing at the front of the bulging plastic front of the disposable diaper.

“That’s fine then, you should still be able to stay in that diaper for quite a while.” Cadance said.

“Off you two go then!” Cadance ordered after a silent pause.
“The two of us will need a few hours at least of uninterrupted time together if I am to do a proper job.”

Rarity exchanged a glance with Fluttershy, the both of them contemplating just what Cadance had in mind for the filly.

As the two of them got up to go, Rarity with her still messy butt and crotch and Fluttershy with her thick, heavy diaper, Rarity turned to Sweetie Belle who was sitting there not knowing quite what to say to any of the ponies around her and looking a little concerned for her life.

Rarity smiled at her sister whose lips were smeared with an Alicorn’s poop.

‘Lucky little filly!’ Rarity thought.

“Have fun, enjoy yourself!” Rarity said quietly.

As the two friends were showing themselves out of the room to return to the central lounge, Rarity turned back for a last fast glance at Sweetie Belle and her new and unexpected, (to her) tutor.

They were already making out again.