Twilight paced a lot, this much was an understatement. The mare credited her habit of pacing for being the sole reason she did not become overweight in her younger years since exercise and her had not become friends yet. But today she was burning quite a few calories, as well as the last dregs of her sanity.

“Come on come on, why won't you work?” She cried, her horn fizzling as the heat suppressant spell sputtered for the fourth time.

She growled and tried again, pouring way more power into the spell then what should be necessary, only for the spell to sputter again. A stream of sparks shot from her horn, bouncing harmlessly across the ground. “Augh!” She cried, stomping her hooves in rage and looking for something to break.

Slowly her anger faded as realization settled in, causing her to sigh deeply and fall to the floor. “This can't be happening, Celestia said my heat should only come once every thousand years! It hasn't even been ten years since my ascension never mind a thousand!”

She groaned, letting her face hit the floor as she continued to moan, vaguely aware of the puddle forming between her back legs but lacking the ability to care about such a development. There she lay for several long minutes, her mind working through every calculation and idea she could up with. Yet no amount of changes to her heat suppressant spell could possibly deal with the amount of heat she felt and every idea she came up with ran into a similar roadblock. Nothing could truly handle an alicorn’s heat, this fact was absolute, and completely unconquerable.

A knock came from the door behind her, making Twilight groan and wonder who was bothering her in her private tower. She had, after all, put up a rather assertive sign and everything.

With a sigh the alicorn turned her head to the side and yelled. “What?” At the top of her lungs.

“May I come in?” Called the familiar polite voice of her former mentor.

Twilight frowned and ran a hoof down her face. “Just a sec!”

The alicorn pushed herself to her hooves and with a flash of her horn banished the small puddle she had accidentally made in the middle of the floor. She turned, quickly wiping away all evidence of the heat suppressant spell she had been working on, and stuffing away any of the papers she had involved in the process. Next she ran a towel through her mane and over her brow before straightening her spine and standing tall. “You can come in!”

The door creaked open to reveal a surprisingly gravid Celestia, who’s belly hung low enough that it very nearly brushed her knees. Thankfully it wasn't as wide, allowing the celestial alicorn to just barely slip through the door without the need of grease.

“It has only been a few days right?” Twilight asked, glancing at a nearby calendar. “I knew I was up here for awhile but surely I couldn't have been up here for long enough for your pregnancy to advance this far.”

Celestia chuckled, sending her enormous belly heaving. “You've only been in your study for two days, not long at all.” The alicorn smiled faintly and ran a hoof over her belly. “Your brother simply has a very, very healthy output.”

Twilight glanced down at the mare’s belly, noting the way that it shook as if half full of some viscous liquid. “I did not need to know that.”

Celestia giggled, noting the way a hint of a blush edged onto Twilight’s cheeks before being quickly dismissed. “Do you have a sitting area set up by chance? I fear as though this weight is beginning to get the better of me.”

“Oh yes, right this way.” Twilight turned and trotted towards a more secluded area of the library, not noticing the way her tail swished with excitement.

The elder alicorn smirked and slowly trotted after her younger, casting a curious glance at the various formulas, alchemical ingredients and stacks of books that littered the mare’s personal tower. Celestia’s sharp and experienced mind was more then up to the task of divining the reason for the various strange and varied spell formuli and she easily figured out that this must have been where Twilight had done the majority of her research for the spells that Celestia had requested. Something caught her eye as she passed an area of her work space that had a fresh package of quills set aside, and all papers and black boards had been wiped clean or gathered up and tucked away out of a bulging drawer.

Hmm, what are you up to Twilight? Celestia thought, before turning to her former student who eyed her with concern.

“Are you alright Tia?” She asked, glancing down at the mare’s knees as if they were ready to give out at any moment.

Celestia smiled, proud that her student had grown up to be the kind and patient mare she was today. “I’m fine, just curious as to what you were working on.”

“Oh that's just some new avenues of research that opened up since first delving into the interaction of potions and traditional enchantment spells.” She said, gesturing to the mass of work that cluttered her tower. “It's nothing right now but there is great potential in this new field if only I worked out a few of the kinks that still hold it back.”

Twilight gestured to the sitting area where all the pillows had been pilled in the corner, the table pushed aside, allowing for someone with even Celestia’s massive stomach to pass by without issue. “Please, sit. I will gather more pillows from my old room.”

Celestia’s chuckled and shuffled over to the offered pile. “I’m not that far along you know, I can still take care of myself.”

The younger mare was about to launch into an apology only to catch the hint of Celestia’s trademark impish smile. “You tease.” She giggled. “I’ll be right back.”

Celestia watched the other alicorn leave, noticing the way her back legs were pressed firmly together and her tail held tight between them, as if hiding something. Not like that did her much good, as Celestia could easily tell from the way she walked that Twilight was no doubt sopping wet, her body no doubt screaming at her to be knocked up. Celestia smirked, her nostrils flaring as she smelled just how aroused Twilight truly was. She must be nearly burning up by now. The elder alicorn averted her gaze, sighing in pity at the suffering her student must be no doubt going through at this moment.

The larger alicorn quickly arranged the mass of pillows into a more comfortable position before gently slipping down and laying on her side. The mare sighed as she felt the enormous weight slip from her back and settle on the soft pillows. After shifting her hooves around, it didn't take long for Celestia to find a comfortable position, one that had her massive stomach and heaving breasts presented for all the world to see. The alicorn smirked at the sight of her lewd body before pulling her legs back a bit and using her magic to push her breasts a little further up, displaying them a bit better.

She dragged the table back into position, before looking up just as Twilight walked down the spiral staircase, her aura containing several large sitting pillows. The young alicorn had a cautious smile on her lips, her gaze distant, as if she was thinking of something that took all her attention. When she turned to Celestia though that concentration waned, her smile falling, as did her jaw.

Celestia smiled seductively, gesturing to the spot next to her. “Oh good you did have some more pillows. I would have hate to have hogged them all for myself.”

The alicorn’s words seemed to draw Twilight from her daze, her eyes tearing themselves away from Celestia’s massive stomach. “Oh uh, yeah.” She lifted the pillows. “I got plenty.”

Twilight winced at her social fo pax before turning and pointedly looking away from Celestia, devoting her attention to assembling her pillows in such a way that didn't leave her facing the elder alicorn’s back end.

An act that Celestia seemed to see coming and easily adapted to, shifting her weight and the pillows under her in such a way that further displayed her watermelon sized tits. Noticing that she was getting nowhere Twilight gave up and shot the alicorn a silent glare before finally taking her seat with a frown.

Wearing her trademark smirk, Celestia leaned a little closer. “So, how is the heat treating you?”

Twilight blushed, raising her chin in the way that Celestia had taught her would display an air of confidence. “I don't know what your talking about.” She said simply, masking her emotions well.

Not well enough to hide them from Celestia though. “Twilight, you do not need to suffer alone, I can help.”

The stiff upper lip and look of confidence remained for a few more seconds before Twilight turned and looked her mentor in the eye and sighed. “It's terrible. At first it came out of the blue and ruined a few study sessions.” She groaned, her eyes falling. “But now it's all the time, I hardly sleep, my appetite is gone and my very mind feels dirty.”

Celestia chuckled. Leave it to Twilight to be worried about missing a few study sessions. “It's alright Twilight, I know how bad it can be.”

“How do you do it Celestia?” Twilight groused. “It's torment, physical and mental agony the likes of which would put dad’s jokes to shame.”

The elder alicorn rolled her eyes and placed a confident hoof on the other mare’s shoulder. “Such is the trade off for immortality and power beyond the comprehension of mortals.”

Twilight frowned, shrugging off Celestia’s hoof. “It's gotten so bad that I was actually thinking of utilizing a coma inducing spell just to wait it out.”

That made the elder princess raise an eyebrow. “Are you sure your okay with missing an entire year of your friends and family’s lives. They have such limited time as is.”

“No.” Twilight sighed. “I couldn't actually leave them, no matter how bad this is. I guess I’m just angry it's come so soon.”

“I am sorry about that my dear. If I had to guess I would say that our close proximity has aligned our biological clocks much like a group of mortal mares.” The playful smirk returned to her lips. “Why don't you just get knocked up? Foal birth isn't as bad as it once was and you could always give it away after it was born.”

Twilight just looked at her. “Do you really think I would do that?”

Celestia chuckled. “Not really, but it is a genuine option that you should think about. It could be anonymous, there are plenty of donors available and we could simply transport the egg once you've been impregnated.” Celestia rolled her hoof dismissively. “Think of it as playing a surrogate and helping some poor mare who can't have her own foals.”

“That is nice, but I’ve always dreamed that the night I was erm, inseminated, would be a romantic one with my significant other.” A flash of something unpleasant flashed through her face, drawing Celestia’s attention.

“What is this? Is Twilight Sparkle not the virginal mare I always imaged?” Celestia gasped dramatically, covering her mouth with a hoof.

Twilight giggled, looking up for the first time in minutes. “No, I’m afraid I’ve felt the dreaded touch of that most carnal of pleasure.” Celestia gasped again, placing her hoof against her forehead as if she were on the verge of fainting. “And it wasn't exactly something I would brag about.”

“That is most unpleasant my dear. I myself simply love everything that comes with being pregnant.” She smirked, running a hoof down her side and over her belly, drawing the other alicorn’s eyes lower. “I think it fills out my form quite nicely. What do you think?”

Twilight gulped, trying desperately to pull her gaze away but finding the attempt to be an utterly useless gesture. “You look very nice.” She muttered weakly, staring intently at the elder alicorn’s numerous curves.

“Oh? You don't think I’ve grown a little too plump?” Celestia asked, grabbing her stomach in both hooves and giving it a shake, making it quake like a bowl full of jelly. “Luna rather enjoys my extra curves but I am less convinced that they look good on me.”

“N-no!” Twilight yelled suddenly, only to notice she was suddenly standing and forced herself to sit once more, pushing down the display of emotion. “I mean, you look amazing, spectacular even.”

Celestia smirked, using her back leg to push her breasts a little forward. “Really? Luna teases me about my breasts being as big as a sow’s.” She pouted dramatically, looking down at her breasts that had grown considerably in a matter of days.

“I-” Twilight blinked, found herself nearly hypnotized by the enormous, pendulous orbs that hung between her former mentor’s legs. “They are nice.” She responded robiticly, using her hoof to manually tilt her head up and look Celestia in the eye.

“That doesn't sound like the Twilight I know and love. Why don't you give them another look and tell me how you really feel.” Celestia said with an innocent smile, drawing the other mare’s eye down with a hoof, before using said hoof to rub her belly in a slow sensual motion.

Twilight couldn't help but gawk, some primal part of her crying out in envy, telling her that she should be more like Celestia. She should give in like Celestia, become heavy with child like Celestia, to feel her breasts swell far past their diminutive size as Celestia’s had. It felt so good just to stare, to imagine that she was Celestia, her body reminding her that the heat would be over in a moment if only she gave in.

The distant sound of Celestia speaking once more knocked Twilight from her stare and she gave her head a hard shake. “I’m sorry what?” Twilight muttered.

“I was just asking if you had any tea. I’m afraid that even with my belly full of your brother’s seed I still find myself thirsty.” Celestia lamented.

This time Twilight didn't even bat an eye at the comment about her brother’s seed, a small blush growing steadily across her features. “Err yeah, one sec.” She mumbled, getting up and trotting off towards the small kitchenette, no longer having the presence of mind to hide her leaking arousal.

Celestia held back a giggle, watching as Twilight walked away, her tail swishing excitedly, her mind awhirl with images of Celestia’s body. “I still got it.” Celestia whispered to herself.

It didn't take long for Twilight to return, this time holding a pot of tea and two cups, her face expressionless save for a slight smile that she quickly stifled. “I hope you don't mind raspberry tea. It's all I left behind after moving most of my things to Ponyville.”

“Of course.” She sighed suddenly. “But I’m afraid my magic is a bit on the fritz at the moment, would you mind pouring it for me?”

Twilight blinked, knowing instantly that the line was likely a bold faced lie. Yet when she looked at the other mare’s pouting face she couldn't help but feel the pull as her eyes wanted to travel down the elder alicorn’s body. She found herself nodding before she could think of an excuse and trotted a little closer, leaning down to pour the for the other mare.

“Come closer dear. You don't want to spill after all.” Celestia remarked innocently.

Twilight took another hesitant step, now less than a foot away from the domineering alicorn and her absolutely massive belly. She gulped, looking down at the cup and forcing her attention on the small object. Lifting the pot, Twilight was about to pour the tea when Celestia spoke again. “Why don't you pour it without your magic. I don't know why, but tea always tastes better when poured without it's aid.”

Twilight knew once more that such a line was complete nonsense, but feeling her gaze drawn lower once more she brushed aside the silliness of the request and did as she was told. All while wanting desperately to escape back to her seat far from Celestia and her stupid sexy belly. “Sure.” Twilight muttered.

She took another step forward and gripped the pot in her hooves, pouring a thin stream of tea into the mare’s cup while trying not to stare. With the cup now full she put the pot down and was about to stand when she felt Celestia’s hoof touch her cheek and gently caress her face, running down her neck. “You can touch me, if you'd like.” Celestia whispered huskily.

The young alicorn gulped, glancing down at the other mare’s body before extending a hoof, only to retract it at the last second. She glanced up at Celestia one last time, receiving a wide gentle smile when she did. With newfound confidence she reached down, tracing her hoof down the other mare’s chest and lower, to her belly.

“That feels wonderful.” Celestia whispered, her eyes only half open, a shiver running up her spine.

The young mare hesitated, her hoof lingering for a second before going a little lower, pressing against Celestia’s soft flesh. Going down further, the alicorn’s belly only grew softer, until finally Twilight’s hoof could actually sink into her fur, her cum filled belly nearly swallowing up her hoof. Twilight pulled back slightly, only using the tip of her hoof to gently caress the other mare’s belly, her tentative touch trailing in slow light circles. Eventually she worked up the nerve to go a little lower, her hoof nearing the other mare’s breasts before pulling back suddenly.

With a fierce blush on her face Twilight sat down hastily, busying herself with pouring her own tea and trying to suppress the heat that bloomed across her face.

Celestia shuddered in pleasure, giving her lips a slow seductive lick before sighing. “That was nice.” She whispered.

Twilight pot the pot down, biting her lip in order to stifle the lewd comment she had been seconds from voicing.

“I noticed you don't have milk for you tea. Would you like some?” Celestia asked politely.

Twilight cocked her head. “But you didn't bring any with you?”

“Oh but I did.” She lit her horn and hefted her large breasts. “I made my own, would you like some?”

The young mare gulped heavily, trying desperately the nearly overwhelming urge to say yes. “Yes, please.” And failing utterly.

The elder alicorn’s magic grew and she gently brought the other mare’s teacup next to one of her teets before giving it a gentle squeeze. Causing a thin stream of milk to spurt into the cup, and a long moan to slip past her lips. With another shudder of pleasure Celestia gave the teacup back to Twilight, smiling all the while. “I hope you like it, I know I did.”

Twilight bit her lip, looking down at the now milky white cup of tea she held. Or at least it had been tea, now it was more like milk with a bit of tea in it. She gulped one last time, not wholly sure why she was doing this but unable to stop herself. Bringing the teacup up to her lips caused her to get a strong whiff of the potent milk that made up the majority of her drink, bringing images of wildflowers and the sweet scent of summer.

The mare couldn't help but linger there for a few seconds, unable to stop smelling the delicious aroma. A light giggle made her remember what she was doing though and the young alicorn took a tiny sip of the milky brew. Her eyes went wide and her jaw fell open, then a second later she threw the rest of the drink back in a single massive gulp.

“Someone enjoyed their milk.” Celestia quipped.

“That certainly was… interesting. I don't suppose you could possibly, maybe…” She tapped her hooves together awkwardly, glancing down at the floor. “Bottle some for me?”

Celestia opened her mouth to speak only to be caught completely off guard. “I could. Remind me tomorrow, for now we have something more important to talk about.”

The young mare ran a hoof across her forehead, wiping away the perspiration that gathered there. “What do you mean?”

“Namely your heat and what you plan on doing about it.” She pointed out, adopting a surprisingly serious expression.

Twilight sighed and looked down at her empty tea cup forlornly. “I don't know.”

“Why not simply ask Shining Armor to help you with this?” Celestia stated

Twilight gasped. “Tia! He's my brother.”

Celestia shrugged. “You are clearly aroused by the thought of him fucking a couple babies into you.”

“B-but that's inbreeding!” Twilight shot back, feeling a hot blush spread across her features.

The elder mare simply shrugged once more. “I wouldn't worry about that. I’ve had tons of Luna’s foals and vice versa. The only reason we haven't done so again is that the offspring were always mortal and Lulu and I are rather looking forward to immortal babies.”

Twilight’s jaw hung open and she tried to speak repeatedly, only to find no words, leaving her sitting there, gaping like a fish for several seconds. “S-still.” She finally sputtered.

“Becoming an alicorn changes a considerable amount of your genetic code, turning ponies that were related to very distant relatives.” Celestia grinned slyly. “And in the case of you and Shining Armor, you aren't even distant relatives, more like different species entirely. Ones that just so happen to be able to interbreed relatively easily.”

“Okay wow, that is a lot to take in.” She shook her head violently. “Still. What if ponies found out?” she blanched, shrinking slightly in her seat. “What would my parents think?”

“I wouldn't worry about that part.” Celestia said dismissively. “As for the public… Your an alicorn Twilight, we hold absolute control of government and have access to the most powerful magic in the history of Equestria. It would be child’s play to keep this secret if you wanted to.”

“That is true…” Twilight mumbled, tapping her chin thoughtfully.

“And if you really wanted we could always create some fanciful tale of a visiting diplomat who swept you off your hooves and left you.” Celestia sighed. “I’m sure your friend Rarity would buy it in an instant.”

Twilight giggled. “That is true.”

“Or more realistically we could come up with whatever story sounds the most likely, to avoid potential scandal.” Celestia shrugged, and sipped at her tea. “Or you could simply not care like Lulu and I.”

The other mare blushed. “Yes well, we can't all be as shameless as you two.”

“Ooor.” Celestia smirked. “We could always say I did it. Half the castle is convinced it's only a matter of time anyway.” She giggled. “We could probably make a good amount of bits if we played our cards right.”

“You wouldn't.” Twilight rebuked.

The older mare’s smirk only grew. “Stars know I would.”

The heat that Twilight had been doing her best to ignore suddenly exploded to the forefront of her mind and she couldn't help but shudder at the thought. Images of her stomach growing to the size of Celestia’s, the titular alicorn’s foals inside her belly. She would be lying if she said she hadn't thought of it before, or fantasized about it before, or wished desperately it hadn't happened before.

She gave her head a shake and smirked back at the older mare. “You tease. Stop trying to make me even more hot and bothered, I don't need help in that regard.”

Celestia giggled into her hoof. “Oh you are too easy to tease.”

The purple mare puffed up her cheeks, filling them with all the indignation she felt.

Making Celestia laugh even harder.

“Still.” The elder mare remarked. “Even if you got knocked up today we would still have a considerable amount of time to figure it out. How long were you staying in Canterlot?”

Twilight tapped her chin thoughtfully, her blush slowly vanishing. “I was thinking of another month or two anyway.”

“See? That is plenty of time to come up with a plan or a cover story.” Celestia pointed out.

“I do have plenty of projects on the go…” Twilight looked around, her eyes growing distant as she thought about it more.

Celestia smiled, watching the gears turn in her former student’s head as her face went through various expressions before settling on one of deep contemplation. The alicorn sipped the last of her tea, a sudden rumble from her stomach reminding her of where she was supposed to be. She pushed herself up slowly, feeling the immense weight of her stomach settling in once more.

“Though I would love to stay and chat I’m afraid I have a date with Luna in an hour and I must be going if I want to be there in time.” Celestia remarked.

Twilight gave her head a brief shake, brushing aside the ideas that swarmed in ehr head.. “Oh, enjoy.”

Celestia rolled her eyes, noting that Twilight seemed to retreat back into her thoughts almost immediately. As she passed by, the alicorn ran her tail across Twilight’s face, drawing her attention up to Celestia’s sopping wet cunt and still slightly parted lips.

The young alicorn stared in awe as Celestia passed, unable to pull her eyes away. She watched in silence as the elder mare trotted to the door, her legs slightly parted, allowing her a good look at her swinging teets. While her tail swished to and fro, giving Twilight an occasional glimpse of her gaping pussy, having no doubt recently enjoyed the company of her brother.

The last thing the elder mare did was shoot Twilight a wink over her shoulder before she slipped through the door, her enormous sides only barely managing to sneak through the portal.

The arousal that had been at the back of Twilight’s mind for the past few minutes roared to the forefront, images of Celestia’s enormous belly and swollen teets fueling her desires. With a groan, the mare collapsed to her pillows, grinding her teeth in annoyance, and cursing her tease of a mentor.

Something Celestia heard from behind the door, which in turn drew a chuckle to her lips. I will have to tell Luna about this, she is going to be so pleased. She thought to herself before turning and beginning the arduous task of making it back to their apartment.

Cadence’s apartment was never meant to be an apartment, serving as little more than a child’s room until such a child grew out of it without moving out of it. So when Shining Armor groaned in mixture of exhaustion and pain the room was filled with the sounds of his agony. The stallion reclined in his wife’s bed, rubbing a hoof over his engorged balls.

The spells, potions and the events of the last few days had taken their toll on him and he was left completely drained, both metaphorically, and physically. Coupled that with fact that Twilight’s anti exhaustion spell had finally run out and the stallion was nearly bedridden yet unable to sleep. His thoughts lingered on his sister despite his attempts to distract himself, making him unable to truly relax.

He reached into the pile of books he had brought to bed with him, grabbing one at random and hoping it would help keep his mind off his incredibly attractive sister and those round kissable lips of hers. Pulling the book back his smile faded the instant it settled on the cover.

It was purple, the exact same shade of purple as his sister’s coat.

With a groan he tossed it aside, his cock twitching as his thoughts once more lingered on the forbidden fruit. He shot a glare down at his other head, glaring at the appendage as it peeked from his sheethe. Considering masterbation only earned him another sigh of exasperation as he felt just how truly tired his body had become.

“The spirit is willing, but the flesh is spongy and bruised.” He quipped, reminded of a quote from a fellow junior officer after being told to do another twenty laps of PT.

It was obvious that he would receive no relief today.

With yet another sigh he further reclined on his mound of pillows before wincing and readjusting the ice pack on his lower back. With the pack now in a better spot, and actually doing something to aid the throbbing pain in his hips the stallion was able to relax somewhat. The pain reluctantly dying with the aid of the enchanted ice pack, allowing him to shift his hips without fear of further agony.

He chuckled at the thought of just how ridiculous his life had become. Here he was, mentally complaining about having sex with too many beautiful mares. Who would have thought he'd be here today, whining about something that most stallions would kill for.

Shining Armor leaned back a little further, staring up at the ceiling as his mind drifted back to the events of the last few days and the most recent announcement that had rocked his world. He was a father several dozen times over and the three princesses’ he had bedded had stated that they all wanted more, not like that was possible but the fact that they wanted it made him hot under the collar.

Sure, such an announcement should have been an obvious one, he had after all finished inside them enough to knock up an entire village of mares. Yet the announcement that he had fathered enough foals to field his entire hoofball team was still a little jarring. He was half tempted to pinch himself to test if he was dreaming, but the pain in his lower back assured him of that already.

As he lay there a sudden image of an entire army of mini Shining’s playing hoofball came to mind, making the stallion chuckle. Though now that he thought about it they would all be female, as Celestia had informed him that there simply was no such thing as a male alicorn. So maybe not hoofball but uh figure skating?

No that was sexist, his progeny could do whatever they wanted and buck any gender norms they felt like. The thought of an entire hoofball’s team worth of alicorns all skating while throwing around a ball came to mind, making him laugh out loud.

The stallion slowly shook his head, thankful that in the time his imagination took to conjure images of figure skating hoofball players his back pain had dulled to little more then a light throb. Gently closing his eyes the stallion wondered if he would be capable of catching a few Z’s before one of his lovers trotted in and asked for another deposit from him.

And maybe that wouldn't be too bad, he mused. It would take more out of him but then again the prospect of engaging in another bout of sex with one of the most attractive ponies on the planet certainly had it's appeal.

The sound of keratin against wood jolted him from his thoughts and he quickly threw a blanket over his enormous balls and budding erection. With his shame contained he cleared his throat and yelled. “Come in!”

The door to his left cracked open and in popped the familiar horn followed by head, of his sister who smiled faintly at the sight of him. “I hope I’m not interrupting anything.” She whispered.

Shining shook his head. “No, I’m just relaxing after a rather demanding morning.”

The purple princess blushed and took a step inside, closing the door behind her.

Something seemed off about the alicorn and Shining could tell she was walking differently. Always keeping her back legs pressed together, a sheen of sweat covering her brow, something the alicorn quickly remedied with the back of her hoof. When their eyes met once more, Shining could instantly tell that the mare was nervous about something as she looked away almost immediately, as if he had caught her hoof in the cookie jar.

She opened her mouth to speak only for no words to come out, a second later she wilted, closing her mouth and pursing her lips.

Shining knew the symptoms of her panicked worrying all to well and with a roll of his eyes he smiled as warmly as he could manage. “How is my favorite sister on this fine afternoon?” He asked warmly.

The alicorn smiled back, only for that smile to fall away a second later. “Good. Distracted, but good, and yourself?”

That was never good, but he knew better then to come out and ask about it.

“Sore, very, very sore. But other then that I can't really complain.” He remarked.

Twilight’s ears perked up and she smacked a hoof against her face. “I totally forgot to renew your endurance spell. Would you mind if I recharged that for you?”

“Uh sure, if you don't mind.”

The alicorn nodded, lighting her horn and a second later a burst of magic exploded into the air before snaking it's way over to Shining’s body and seeping into his every pore. The magic slowly dissipated, as did the stallion’s lingering aches and pains that had still troubled him.

“If you will hold still for a second longer I can ensure it lasts longer than last time.” Twilight offered.

Shining Armor was about to agree but there was something about the request that didn't quite feel right. He may not be the prodigy his sister was but he was still a learned mage and he got the feeling she was about to cast a different spell entirely.

He shrugged, trusting his sister. “Go ahead.”

The alicorn’s blush was rendered nearly invisible by the glow of her horn, then with a flash larger then what seemed necessary, another wave of magic seeped into his body. This time it seemed to focus nearly entirely around his crotch, but he couldn't be sure if that was coincidence due to being rendered nearly blind by the power of her spell.

Twilight stowed her blush deep down inside, half tempted to simply out herself and explain that she had just cast a series of enchantments on his body. It was in line with the rest of the spells she had cast before so explaining it wasn't wholly necessary, right? She shook such thoughts away, she would tell him later, if she didn't say what she had came here to say soon she would no doubt lose her nerve.

“I’m just going to check if everything is working.” Lighting her horn Twilight glanced down the male’s body, pretending to do a quick scan.

The stallion merely nodded, remaining still as he felt the spell go down his body, starting from the tip of his horn and going down until it unexpectedly sputtered around his crotch area. He blinked, looking up to find a furiously blushing alicorn staring at something between his legs. He followed her gaze and found that his cock had begun to harden without his knowledge or consent, peeking out from under the blanket. With a grunt of embarrassment he pulled the blanket up over his lower body, obscuring the slight bulge his cock made.

“Not to sound rude or anything but why exactly are you here?” Shining asked, hoping to drag attention from his cock.

The alicorn shook her head, pulling her gaze from one of the stallion’s heads to the other one. “Oh um. I just wanted to test a few spells and check on you. Celestia expressed concern that they were running you a little ragged and that the endurance spell may have been keeping you up at night. This new variant should allow you to become tired whenever you desire.”

“Daww, Sunny really is the sweetest.” He remarked, smiling softly as his mind drifted to thoughts of the titular mare.

“Sunny?” Twilight asked.

“It's just a pet name we came up for Celestia.” The stallion blushed slightly. “She really is the cutest.” His blush suddenly doubled in size and he looked down. “Well, second cutest anyway.”

“That certainly is an interesting way of referring to Celestia…” Twilight remarked.

“I suppose it is kind of odd but we've grown so close after these past few days. This whole changeling thing is kind of scary-” The alicorn opened her mouth to speak but quickly slammed it shut. “-but kind of nice in a way. I’ve never been closer to my wife, or Celestia and Luna.” He rubbed the back of his neck awkwardly. “Even if it has made my life even more complicated than usual.”

“And what does Cadence think of all this?” Twilight asked curiously.

“Cadence seems to enjoy and encourage me getting closer to Celestia and Luna. It's strange, but I suppose the princess of love would say that.” He chuckled. “Even if it has brought up some interesting questions about the nature of our relationship. Relationships?” He shrugged. “I’m not wholly sure which is which.”

“What do you mean?” Twilight asked.

“We don't really know yet to be honest with you.” He sighed. “It's all rather complicated.”

Twilight looked like she was about to say something only to once again struggle to find the words she wanted to speak. Together the pair both sat in silence for several long moments, their minds both turning with the unasked question still hanging in the air.

What was their relationship now? It was clear that it had evolved since the initial, knock up/get knocked up, plan that it had begun as, but what did that mean, and what could it mean?

Shining Armor shook his head, dislodging the cloying thoughts for the moment. “Why are you really here?”

“W-what are you talking about?” Twilight asked hesitantly. A glare from her elder sibling made her sigh. “That obvious huh?”

“Your not bad, it's just an older brother thing.” Shining Armor said with a smirk.

“Do you mind?” She gestured to the spot on the bed next to him.

Shuffling over, Shining Armor patted the spot on the bed. “Sure.”

She nodded and slipped into the bed beside him. “It's kind of awkward to talk about but…”

Shining smiled and gently took his sister’s hoof in her own, giving it a gentle squeeze. “You don't have to tell me if you don't want to.”

Twilight breathed deeply before just spitting it out. “I’m in heat. Not just regular heat but alicorn heat.” she sighed, letting go of Shining Armor’s hoof. “Apparently my proximity to Celestia and Luna caused my time to come a few hundred years before it should have.”

“Wow, that uh sucks. I guess that makes sense how Luna and Celestia managed to get knocked up so quickly.”

“Err yeah, it worked out well since the whole changeling thing and they wanted foals. I’m less sure. Sure I wanted a foal and that would ‘cure’ this heat, but I don't want a foal with just anybody.” She muttered nervously, gripping the bedding with both hooves and squeezing it absently.

Shining Armor shrugged. “Well if you need a uh, donor let me know.” He gulped. “Since you are an alicorn it's like we aren't even related, more like different species entirely. Ones that just happen to be able to interbreed.”

Twilight nearly groaned aloud, images of her conversation with Celestia flashing through her mind. She made a note of teasing Celestia back but otherwise pushed that thought aside for now, it didn't help her now.

“Are you sure?” She asked hesitantly.

“Yeah, of course. Since your an alicorn it's like your some sort of super distant relative.” He grinned. “Like aunt Star Fire and uncle Corona.”

The alicorn chuckled. “They are only second cousins, this would be more like third cousins.” She shook her head. “Would you be really alright with knocking up your sister though?”

“Sure, it's not a big deal. I mean until last week I never thought I’d ever have sex with anypony other then Cadence but now I’m a father like a bajillion times over already.” He laughed, taking Twilight’s hoof in his own. “So if that's what it takes to cure you of this heat, then it would be a small price to pay.” He winked, making the alicorn’s heart melt.

“And it wouldn't exactly take long either if you um didn't want it to.” She squeezed his hoof back, blushing hard.

“That's pretty much a given, your a gorgeous mare Twilight.” He blushed a little, looking down. “Plus I admit there is something kind of sexy about how tall you've gotten.” Shining Armor ran a hoof down the alicorn’s foreleg, causing her to shiver in pleasure. “Nevermind these gorgeous legs of yours.”

“Oh really?” She smirked, extending her legs and striking a pose that she had seen Cadence strike before. “How do I stack up?”

The unicorn blushed hard, his eyes roaming down his sister’s surprisingly well muscled body and down her lithe, well defined legs. “You are amazing, Twilight. Cadence is a bit taller but you definitely have more definition.”

Twilight crossed her forehooves over her chest, frowning at him. “Is that a fat joke?”

Shining Armor merely rolled his eyes. “No, that was not a fat joke. You have been adventuring for years Twilight. You are far buffer then you think you are.”

She blinked, looking down and flexing her limbs one by one. “Huh. I never really thought about it before, but when your fighting monsters and world ending calamities every other week for a decade that will happen.” She lifted a forehoof and flexed it, feeling and seeing the muscles ripple just beneath her flesh.

Shining Armor merely shook his head slowly, a little taken aback by just how strong his little sister was. “That it would.” He remarked lamely.

“So, um, could we do it today? By chance?” She asked, her confidence disappearing in an instant.

“Absolutely!” He announced with a smile, throwing aside the blanket to reveal his semi hard cock already standing at half mast.

The purple alicorn giggled nervously at the sight. “Did I do that?”

“You sure did, and your only making it bigger with each second you stare.” He pointed out.

Sure enough, the longer she looked the bigger it got, until the already intimidatingly large cock grew to truly mammoth proportions. The longer she stared the more she was sure it had grown larger than ever before, and she wondered just what had changed.

Taking a quick visual reference, Twilight realized that it was perfectly adapted for her body and would probably fill her vaginal canal completely, putting the tip of his cock directly at the entrance to her womb. She looked up at Shining, only to find his head rolling about on his shoulders, his eyes having glazed over.

“Are you alright Shiny?” She asked nervously, placing the back of her leg against his forehead.

“Yeah…” He mumbled, shaking his head. “It just takes a little bit before my body adjusts.” The stallion shook his head one last time. “Takes a lot of blood to fill this bad boy.”

The alicorn giggled, noting that the paleness she had seen in his face was quickly disappearing. Another glance down at the unicorn’s massive throbbing appendage brought a sudden giggle to the mare’s lips, an odd thought entering into her mind.

“Ya know usually it's not nice to laugh at a stallion’s junk you know.” Shining quipped.

Twilight shook her head. “I didn't mean anything like that, it's just your so small, and it's so big.” She licked her lips. “It looks a little strange on you.”

And indeed it did, the massive size of the endowment was perfect for engaging in coitus with a pony that had a foot and nearly fifty pounds on him, but that meant it didn't exactly fit on a pony of his size. Which left his cock to come up nearly to his neck and growing much, much thicker than it should be able to, altering itself to fit snugly inside an alicorn’s pussy.

“I guess it does look a little strange on me huh?” He stretched out, showing off his large abdominal muscles and his massive cock.

“Your so small.” The alicorn giggled, leaning down and pecking the unicorn’s cheek. “Not like that's a bad thing.”

He groaned in annoyance, clenching his jaw, yet a blush grew on his cheeks. “I am not.” He mumbled.

“Riiight.” Twilight giggled, only to stop suddenly, her eyes lighting up. “Wait just one second.”

“One.” He said with a smirk.

“Har har. That stopped being funny when I was nine.” She rolled her eyes and cast a quick spell that made her stomach glow a faint gold for a second before returning to it's normal and non glowing hue. “Alright, ready.”

“Are you sure your ready for me, I am pretty big and I doubt one lubrication spell will cut it.” Shining looked around. “I’m sure we have some lube around here somewhere.”

The alicorn just laughed. “I don't need lubricant even for your monster of a cock.”

“Oh, so what was the spell for then?” He asked.

“Just something to make sure it takes on it's first go is all. It's an advanced version of my other fertility spell.” She remarked.

“In that case can you cast it on Cadence when she shows up in about an hour? She's just doing a few errands for Celestia right now.” Shining Armor asked.

Twilight sighed. Of course Celestia would plan for this. She shook her head and made a note to find a way to tease the ancient alicorn. Maybe Luna knows of something I can use against her. Noticing her brother was still looking at her she smiled. “Of course, but hasn't she already memorized my other enhancement spells?”

The stallion sighed, running a hoof through his mane. “She does, but she's always lamenting the fact that she isn't as big as Celestia or Luna and wants to change that.”

“Speaking of which…” Twilight winced. “Are you sure your wife would be okay with this? I mean, you are knocking up your sister after all.”

“Pfft no. I've had a standing allowance to knock you up since you were eighteen.” He remarked off handedly.

Twilight groaned, planting her face into her hoof. “Of course she would.” She shook her head. “Your wife is weird.”

“Yes she certainly is something.” Shining Armor shrugged. “So, how did you want to do this exactly, quick and easy or slow and sensual?” Shining wiggled his eyebrows at her, making her giggle.

“I’m not sure, I’m not exactly experienced in this regard.” She sighed. “I’m no princess of love, or have been revered as a fertility goddess, nor have I been described as the princess of passion before either.” Her shoulders slumped and she looked down. “I’ve only even had one encounter before and I didn't exactly enjoy myself.”

A sudden cruel gleam came to the stallion’s eye and he gripped the mare’s shoulders, forcing their eyes to meet. “Who was it, did he force himself on you?”

She smiled faintly, brushing aside his hooves. “No, nothing like that. It was just loveless, with a little too much wine in both of our systems. Turning two foolish ponies into a pair of awkward lovers. And yes, we did use a condom.”

Shining Armor sighed. “Good.” He smirked. “I’m not sure I would have ever guessed that you were the type of pony to even drink wine nevermind do that.”

“Hey!” She smacked his shoulder. “I can be rash sometimes you know!”

Shining Armor just gave her a flat stare. “Really? Because I remember the first time we went to Donut Joe’s and you spent three hours figuring out everything about every donut before finally deciding.”

The alicorn’s face grew bright red and she slapped the stallion’s shoulder again. “Hey I never had a donut before that! I wasn't sure if I would like it!”

“Face it Twilight, you are the most prudent pony in equestria.”

“Am not!” She retorted, her cheeks puffing up as a blush spread across her face.

“Are too.” Shining said with a smirk.

“Would the most prudent pony in Equestria do this?” The alicorn threw open her wings and leapt at the stallion, pinning him beneath her superior weight and using a tiny bit of earth pony strength to press him against the bed.

Her wide confident smile faltered somewhat and she looked down nervously. “Do you mind if I’m on top?”

He rolled his eyes and chuckled, letting himself be pinned. “Communication is good but you could have inferred that I was okay with the position change since I didn't say otherwise. So go ahead and take the reins, unless your too prudish for that.” He flashed the mare a smirk.

“I am not!” Twilight shoved the stallion down against the bed before pressing her body against the stallion’s enormous length, which served to show just how much larger she was as her body easily covered his own.

The alicorn licked her lips and rubbed her body up and down the length of his cock, smiling all the while. She let out a low moan of pleasure as she felt his hard length brush across her exposed pussy. “Are you ready little brother?” She asked coyly.

The stallion rolled his eyes and grinned. “I was born ready. The real question is if you are, little mare.”

A firm hoof kept him pinned against the bed. “You will see little pony.”

She gripped the bed a little tighter, throwing her hips forward and briefly blocking the stallion’s vision with her bulk. The slight tingle of magic of magic suddenly gripped the stallion’s cock and he felt it's not insignificant weight lift from his chest and angle upwards. There was a moment of calm where nothing happened, Twilight’s body going stiff as if second guessing herself, only for ir to vanish a moment later when he felt the alicorn begin to move once more.

She pushed back, pressing herself against the stallion’s thick head and forcing it into her tight canal. The instant his cock met the lips of her pussy he was left astonished by just how aroused Twilight was, as the head of his cock was now coated in a thin layer of the stuff within seconds. With so much natural lubricant it wasn't hard for his cock to find purchase and begin to slip inside.

Gritting her teeth, Twilight pushed back, the emptiness inside her demanding to be filled and with the solution to such a problem so close at hand her whole body seemed to echo that cry. With a powerful surge of her hips Twilight pushed herself back, feeling the tip of her brother’s cock slip inside her. The mare couldn't resist releasing a powerful moan of pleasure at the sensation, between the heat abating slightly and the emptiness receding, she nearly came right then and there.

But if only the head felt this good, then what would it be like to feel her entire pussy filled with his thick stallionhood? The thought was a tantalizing one and the mare instantly threw herself back against her brother’s shaft, spearing herself on it's length and causing several inches to plunge deeper inside her.

She moaned aloud once more, relishing the loss of the heat that had been clawing at her mind for days. When her moaning finally died out and she was about to move once more she could hear a faint sound of pleasure come from Shining Armor. A noise that was somewhere between a grunt and a moan, making Twilight’s lips curl with a relieved grin. Overjoyed to hear her brother enjoying himself she pushed on, her fear of inadequacy dwindling with each passing second.

Rocking her hips back and forth the mare worked herself deeper and deeper down the stallion’s thick shaft, feeling every inch as it slid inside her. With the amount of natural lubricant and her body's insistent demands, it didn't take long for her to feel that enormous shaft of his slip deeper than anything had ever penetrated her before. The mare sighed contently, relishing the feeling of fullness that resonated through her.

“Having fun getting fucked by your big sister?” She asked coyly, smirking down at the stallion.

Shining Armor shrugged. “It's nice, if a little slow.”

She shot him a harsh glare, almost managing to make his mask crack as a smile threatened to spread across his face. “I’ll show you slow.” She muttered, before throwing her hips back once more, this time with far more force.

Several hard inches surged inside her, pushing well beyond anything she had ever felt before. The stallion would normally have been caught off guard by the sudden surge of motion but after the last few sex filled days had thoroughly destroyed his up until now fairly vanilla expectations of sex. So when the alicorn pushed hard enough to make his medial ring slip inside her before looking down at his confidently, he merely shrugged.

“Augh, come on!” She groaned.

“I’m just teasing you Twily, your doing fantastic.” He replied back, running a hoof down Twilight’s foreleg.

“T-thanks.” She blushed hotly. “But I am still going to knock your socks off!”

“Oh really? Because Cadence would be balls deep by now you know.” He quipped.

Her eyes narrowed. “Well see about that!”

With her pride on the line the mare regripped the bed, taking a step back before once more throwing herself into the act, plunging deep on the stallion’s shaft. The first thing she noticed was the lack of the empty feeling that had plagued her for almost a week, then came the fact that she didn't feel the soft sensation of Shining’s fur against hers, or the lack thereof. She glanced back, noticing that despite all her bravado she had several more inches of cock not stuffed inside her. She also noticed that she could see her brother’s cock through the outline of her stomach, the head of which was clearly visible through her skin.

She didn't have the time to marvel over that though, she had more dick to conquer and not much time to do it! With a grunt of determination she used her weight to push herself down and back, feeling inch after inch slowly push inside her. It wouldn't be quite so hard or take so long but she had simply never taken something this deep before and was unprepared for just how big he was.

Shining Armor, meanwhile was stunned to silence, if he had known his little teasing would have worked this well he might have let up a little. Even still, he couldn't bring himself to ask her to stop, her body was tight in a way that the other alicorns simply weren't. Cadence’s body knew well the shape of his cock and even after being enhanced he still slid inside her with relative ease. Celestia was the largest lover he had ever taken and though she was still tight she was quite accommodating. The closest he could imagine was Luna, whom he had inferred from talks with Celestia was more fond of her tongue then his dick.

Nothing could compare to the tightness of Twilight’s pussy and in a way it almost felt like he was having sex with a virgin. She was as tight as one, as ignorant as one, and possessed that same almost manic intensity as one. The thought was an enticing one and he couldn't help but enjoy it more with each passing second. In a way he was taking her virginity, an idea that was made that much more impactful as he felt her slide a little further back, the last few inches of his cock slipping inside her.

Her whole body clenched briefly, their hips nearly meeting with as she finally came close to bottoming out on his cock. He blinked, looking down and finding that same bulge he had seen before had now traveled far up her stomach. Twilight growled in annoyance, she could feel nearly every inch of her brother’s throbbing erection inside her pussy, yet some remained outside. She wanted more, needed to feel full, complete and finally free of the heat, yet her hooves resisted, nearly having gone numb already. Tilting her weight back she used her natural momentum to slide the last few milimetres down, only for both pony’s eyes to go wide as they felt the head of his cock impact the entrance to her womb.

Twilight felt as though her soul had left her body for a split second as she entered the astral plane. A feeling that didn't last long, leaving her panting with lust as she clung to her brother’s chest.

“Are you alright?” Shining asked nervously, picking Twilight’s chin up and forcing their eyes to meet.

She smiled dumly, her head rolling about her shoulders. “This is amazing, you are a million times better then him.”

“Don't worry Twily, I’ll make sure this is a night you never forget.” He said confidently, smiling widely.

“I should hope so, I am going to have your foal after all.” She whispered back, leaning up and gently nipping the stallion’s ear.

Shining Armor wanted to respond or to nip her right back, but it had just hit him. This was really happening, he was really about to knock up his sister with a foal. Rather than be dissuaded by the realization of what was about to happen, he instead grinned a wide and toothy grin. He gently helped his sister to her hooves once more, setting his back legs and angling his crotch to give her a better angle.

The alicorn hardly noticed, too caught up in her own pleasure filled world. She had begun to pull herself up, in preparation of thrusting back down again, yet she had to stop ever inch or so, perpetually caught off guard by just how good it felt. It felt natural, right even, his cock fitting her like a glove, and though she knew this was in part because of the magic she used, it still felt special to her. To her it was as if her entire life had been leading up to this moment, and with that thought in mind the last of her paranoia died.

She was the pony Shining wanted, when she looked down she could see it in his eyes, see the love, the lust, the naked desire. His touch was electric, sending bolts of pleasure through her body as he ran his hooves up and down her body. There was an intensity to the way his muscles coiled beneath her, a love that came out in every breathy moan that past his lips.

By the time she finally manages her first real thrust, burying her brother’s cock inside her once more she felt as though she were mere moments from cumming. She wasn't sure but it was like abandoning the fear and paranoia that plagued her seemed to unlock something inside her, turning every feeling up to eleven.

She placed an unsteady hoof against his chest, breathing hard. “Just, wait a second. I’m close but I don't want to cum quite yet.”

Shining Armor leaned back, putting one foreleg behind his head. “Oh Cadence would have a hay day with you.”

“What do you mean?” Twilight asked a little more defensively then she had wanted.

“She loves ponies with a hair trigger, says they always make for the best lovers.” He chuckled. “Well except me of course.”

Twilight huffed indignantly. “I just happen to have more fun than the average mare.”

“I’m not teasing you, for once. She really does enjoys a pony like you.” He smirked. “Are you ready for the first round to start or what?”

The alicorn ran a hoof across her forehead, wiping away the sheen of sweat that had gathered there. “Oh yeah, I’m totally ready.”

“Right, well you just go ahead whenever your ready little sister.”

“I’m the big sister now remember?” She smirked, using some earth pony magic to fortify her body and allow her to stand without shaking. “I’m bigger, stronger, and a better mage then you after all.”

A sly smirk spread across the unicorn's face. “Then why don't you prove it, little mare?”

Their eyes met and narrowed, the mare wiggling her hips slowly as the two sized each other up. The glares were heated yet there was no tension in the air, not a single bit of negativity to be found in each other’s eyes. Then, the mare smirked and using her wings, threw herself forward, only to reverse direction and use even more force to push herself back down his shaft, their hips connecting once more.

The move was quick, and new and though Twilight felt as though she did everthing quickly she glanced down to find Shining smiling up at her. Confidence secured, the mare continued to throw herself up and down his length, varying her speed, direction, and method. Each time she did she glanced down at Shining, noting his expression and adjusting in times where it didn't look as though he was enjoying himself as much as he could be.

It wasn't long before she could feel Shining begin to thrust back, their hips meeting halfway. Each time they did Twilight could feel the strength behind his thrust, slamming the head of his cock against the entrance to her womb. In minutes the room was filled with the pungent scent of their love making, the mix of sweat and fluids combining to form a potent cocktail of scents. The alicorn breathed deep, her hips moving even while her mind focused on her other senses.

The scent of their love was heavy, and she swore she could smell the raw power of her brother on display. Her hips moved in perfect harmony with her lovers, meeting his at the apex of every thrust, the rest of her body following closely. She didn't even have to think about it anymore, making her smile as she realized she had gone from a jerky, slow movements to this in such a short time made her breast fill with pride.

Closing her eyes, the mare focused on the sensation of her brother’s cock as it slammed into her, over and over. With her sense of sight cut off the sensations coming from between her legs seemed amplified, and Twilight found herself able to feel every bump and groove on Shining’s cock as it pounded into her. The emptiness that had plagued her was nearly gone by now, having centered solely in the one place he had yet to fill, her womb. It felt empty, and it was the last bastion of the heat that had burned her so badly. Rather than be annoyed by the fact that the negative repercussions of the heat still lingered, she merely smiled, knowing it was only a matter of time before even her womb was filled with her brother’s love.

Shining Armor smiled, running a hoof down Twilight’s chest as she moved up and down his shaft, her eyes closed, a smile on her lips. The sight of such a beautiful mare atop him was intoxicating and even after tasting the pleasure of the oldest and most talented lovers in Equestria, he still found himself enthralled by her. The way her hair framed her face, even while in the throws of passion, it seemed to hold to it's semi rigid state, allowing him an unobstructed view as her face contorted in pleasure. The virginal mare had no desire to hold back on her feelings, eagerly filling the room with the sounds of her pleasure.

Moans, whimpers and muttered words were a constant threat to the stallion’s senses and he smiled every time he heard his name whispered between moans. His hooves caressed her fur, his eyes beheld her beauty, his ears were lucky enough to catch every precious sound she made, yet he didn't have enough. He needed to taste her, to let his every sense touch her, only then would they truly know one another as lovers.

His hoof caressed the soft fur of her chest, only this time it did not stop there, he continued on, touching up her chest, to her neck and finally to her chin. The mare’s eyes fluttered open, a question already on her lips, a question that was stifled by a single longing look. Their hips slowed, their bodies moving in a different way as the alicorn bent down, knowing exactly what her brother wanted. An action he eagerly mimicked, happy to see that his training had come far enough they could communicate intention through touch alone.

As her trembling lips sought his own he wondered if it was fate that had brought them here today, it certainly felt as though his life had been leading to this moment.

Then, their lips touched and all such thoughts were dismissed, their eyes closing as they sunk into pleasure’s rapturous embrace.

Their hips stopped, not only that but their entire body’s stopped and if you asked him afterward, Shining Armor would have sworn his heart had stopped for a split second. Yet a second later they pulled back, Twilight having a hint of uncertainty on her face. Shining looked it was not uncertainty towards him. She touched her lips with a hoof, pulling back her limb and staring it in wonder, as if perplexed by the fact that such a simple act would feel so good.

A slight buck of his hips alerted the alicorn to the fact that she had slowed considerably over the last few seconds and she was forced to give her head a shake before moving once more. Their pace quickly resumed it's former pace, with each thrust met by a powerful counter thrust that made both parties moan aloud. This time it was different though, each thrust was punctuated by a slight kiss, a tender touch or some other intimate act that served to draw them closer with each thrust of their hips.

Their joking and jovial tone was completely lost by now, their minds filled with lust and little else.

With her thoughts so utterly consumed it wasn't a surprise that Twilight’s orgasm quickly returned to her without the mare having the attention to keep it at bay. It's return was heralded with a sudden bout of weakness that filled her body, making her legs shake, and her thrusts stutter to a stop. “I’m so close Shiny!” She whimpered.

The stallion, knowing just what to do, grabbed the alicorn’s hips and thrusted up inside her with all the force he could muster. Strength poured through him and even as Twilight nearly collapsed on top of him his thrusts continued to pound into her. When her back legs gave out entirely he still continued, until finally he felt his sister’s pussy clamp down tight around his cock, spasming as the alicorn came harder then she had in years.

“I’m cumming big brother!” She cried.

“I’m close!” He yelled back, biting his lip and continuing to pound into her with every bit of strength he had.

The tightness, the intimacy, the debauchery of fucking his sister, everything came together perfectly but nothing was quite as pleasurable as hearing Twilight’s whimpered moans and small half muttered words. He had reduced her to a drooling wreck of a mare, tongue hanging from her mouth as her eyes rolled into the back of her head. He had succeeded, he had made her feel as good as he did and now he would make her a mother.

With one last titanic thrust he buried himself in her pussy, his cock spasming as his balls contracted, the first of what promised to be a massive load already shooting into her. “I’m cumming Twily!”

“I can feel it!” She cried back, arching her back and pressing a hoof to the bulge his cock made in her midsection.

A second later the first explosion of cum rocketed up his cock and exploded through the thin barrier to her womb, pooling in the deepest reaches of her body. The alicorn’s mind went blank the second she felt the wave of her brother’s cum hitting her womb, signalling that she was milliseconds from being impregnated.

All at once the heat, the emptiness, the nagging misery, all of it was gone, replaced by the most powerful orgasm of her entire life. It didn't even seem to matter that she had came only seconds earlier, her body was so overwhelmed with pleasure that the small refractory period was squeezed even smaller. Her back legs lost all strength entirely and she only barely managed to keep her forehooves from falling suit, the sight of her bulging stomach too much to miss out on.

Shining Armor watched in awe as each surge of cum added a little more padding to the mare’s midsection. Within seconds the significant bulge his cock had made in her body was gone, washed away by the litres of seman flowing into her sister.

A sight that only seemed to add even more fuel to the fires of his lust, making his orgasm grow larger still. He still had enough thought to place a hoof against her chest, helping to hold her aloft and keep her from falling entirely. Something the alicorn was immensely thankful as her orgasm had only increased in strength as time went on.

Her pussy had clamped down with an all but vice like grip on his cock, gripping the organ tightly. It was an undeniably erotic sensation, the alicorn’s body milking him for all it's worth, as if Twilight’s womb was sucking out every drop of cum that it could. He knew such a thought was silly but as he felt litre after litre disappear into her without any end in sight he couldn't help but imagine that it might be truer than he had first believed.

The alicorn had enough presence of mind to cast one last spell, ensuring that not a single drop of delicious cum could possibly escape her womb. With that done she looked down, feeling the stallion inside finally stop twitching.

Only to double take as she saw just how truly massive her stomach had grown already.

“Wow.” They both muttered.

Shining Armor brushed a hoof over the taut surface of her belly, marveling at the fact that she looked several months pregnant already. The stallion had grown rather intimately familiar with the feeling of being drained over the last few loads and he felt as though he had gone several rounds with a hungry Celestia.

“This is crazy, your so big already.” He remarked.

“Yeah.” She whispered, running her own hoof across her massive belly, marveling at it's size and the way it shook gently under the slight touch. “It looks like you knocked me up already.”

Shining chuckled, poking the mare’s stomach and watching as it shook at even the small touch. “Yeah, it sure looks like it eh big sister?”

Twilight giggled back, leaning down and giving the unicorn a kiss on the lips. “It sure does little brother.”

Eventually, strength returned to the mare’s limbs and she was able to keep herself up as she felt the stallion’s length begin to soften inside her. As she felt the massive invader slowly retreat from her passage she leaned down and brought the stallion into another kiss, this time lasting much longer, both pony unwilling to let the other go quite yet.

Only when his cock had grown completely soft and having fallen out of her pussy did they finally break their kiss. With a feeling of distinct loss they both pulled back, shooting each other a look before Twilight lay on her side, beckoning the stallion forward with her open limbs. Something Shining Armor eagerly accepted, slipping into the mare’s warm embrace and nuzzle her softly, the feeling of her squishy belly pressed between them drawing a grin to his lips.

There they kissed, cuddled and generally enjoyed each other’s company without hurry or complaint.

Minutes passed by and neither pony said anything, the silence broken only by the sound of their lips meeting and parting and the soft slosh as Twilight’s belly shifted.

As time blended together Shining Armor absently wondered what he was forgetting, yet a slight nuzzle from his sister turned lover made all such thoughts disappear.

A few minutes later they received a reminder as to what he had forgotten in the form of the door to Cadence’s room opening to reveal the owner of said room staring down at them.

Twilight gulped and waved feedly at the other mare. “Uh hey Cadence.” She muttered.

Shining waved a little more enthusiastically. “Hey honey!”

Cadence’s features were impassive and with a firm hoof she slammed the door shut, stomping over to the bed, her eyes fixed on Twilight. Every step her impassive mask cracked a little more and by the time she was at the foot of the bed she was grinning like a mad filly.

“So you two finally did it huh!” Cadance smirked. “About time.”

Shining Armor just nodded. “I guess you were right hun.”

“Was I really that obvious?” Twilight muttered.

Cadence giggled. “Just for princesses’ whose domain is love.” She paused, tapping her chin. “Oh and the other princesses, and Shining, and your mother, and that one guard-”

“Augh! I get it!” Twilight grunted, pushing herself out of Shining’s limbs and crossing her forehooves over her chest. “What about it?”

“Nothing.” She shrugged. “I just like teasing you.”

The mare’s face grew hot and she was about to sputter out a response when Shining chimed in. “She is pretty adorable when she gets all flustered like that.”

“H-hey!” Twilight sputtered.

“Your right.” Cadence tilted her head to the side, staring at the increasingly angry mare. “The way her cheeks get all puffy and her face goes red is pretty cute.”

“Cut it out!” The adorably angry alicorn sputtered.

“Or what? Your going to steal my husband from me?” Cadence shot back, smirking all the while.

“Yeah!” Twilight dragged Shining over to her side, wrapping a hoof around him. “His cock is mine now!”

“Oh yeah?” Cadence asked, her eyebrow raising.

“Wait, don't I get a-”

“Yeah!” Twilight yelled back. “What are you gonna do about it huh?”

“It looks like we are going to have to establish who the alpha mare is around here.” The alicorn hopped up onto the bed, her gaze narrowing as her stance grew low. “Prepare yourself, usurper!”

Twilight was about to wince and mutter an apology, only to see the same mischievous glint in the other alicorn’s eye that she had seen a hundred times. “Bring it on!” She stopped, glancing down at the mare’s very pronounced stomach, somehow only noticing the fact that she appeared pregnant and ready to pop already. “Are you sure we should be ‘fighting’ when your pregnant.” Twilight asked, adding air quotes around fighting.

“Hmm, good thinking. I suppose another kind of competition is in order then.”

The purple alicorn stifle a giggle, forcing her face to remain an impassive mask of indifference. “What kind of competition?”

“It shall be a contest of wills, of determination and sheer female perseverance!” Cadence raised a valiant hoof over her head.

“So like, your going to resist the urge to nag at me?” Shining piped in.

Both mares turned to him, intent on delivering a jab only to realize that he had managed to snare them in a catch twenty two. If they did bug him back that might be considered nagging, but if they didn't it would seem as though they were playing his game.

With a snort of annoyance Cadence turned to Twilight. “How about we just fuck and make my no good husband watch?”

Twilight nodded. “That sound like an excellent idea.” She glanced at Cadence then down to the bed. “So uh how are we gonna-oof!”

Cadence lunged at her, using her magic to pin the startled alicorn on her back before landing atop her, one hoof against Twilight’s chest. “Like this!”

The princess of love leaned down and pressed their lips together, drawing Twilight into a deep kiss.

Twilight all but fell into the kiss, caught off guard by just how intense it Cadence was. Lips parted, and two mares got to know each other at a deeper level than ever before. A hoof caressed up Twilight’s neck and around to the back of her head where it gripped her tightly, holding her close as the kiss deepened and the purple alicorn melted.

Though she wasn't the greatest kisser in the world she did have some experience adding to that the experience gained from her brother and Twilight was at least semi confident she wasn't garbage at it. Or at least that was her opinion until Cadence utterly destroyed it. Where Twilight was a clumsy dancer just learning the steps, Cadence was a master of a thousand styles and was an absolute master of her craft.

Her every move was snake like in the way that Twilight found the mare coiling about her in one way or another and in no time at all Twilight felt herself twisted around the mare’s hoof. Even realizing this didn't dissuade from just how good it felt to be under the mare’s control. Until all at once the alicorn of love simply pulled back, leaving Twilight gasping, desperate for more.

“My fool of a husband tried to teach you a few things didn't he?” Cadence remarked.

Twilight nodded. “Sort of…”

Cadence giggled at the glare her husband shot her. “He means well but he dances the same way he kisses.” The mare sighed dramatically. “He just goes around and expects you to follow him, but that's not how kissing works.” She took Twilight’s hoof in hers and brought it up, then down in a long sweeping motion. “To kiss is to dance, and a dance is a partnership, a give and take.”

“Oookay.” Twilight muttered.

“Let's try again shall we?” Cadence offered, making Twilight’s eyes light up.

“Yes please!”

Shining Armor grumbled silently, half tempted to ask if he could join in and he would have, if it wasn't incredibly hot just sitting back and watching his wife and sister make out. So instead he just sat back, stroking his slowly rehardening cock.

Minutes flew by as Twilight received a master class in the art of the kiss, going from an amatuer to experienced in no time at all. By the end of it her mind was blown and she lay on the bed, Cadence laying next to her running a hoof across Twilight’s chest.

“Ready for the real thing?” Cadence offered.

“Actually…” Twilight motioned for the other mare to come closer, something Cadence eagerly obliged, allowing Twilight to whisper into her ear.

An inaudible conversation passed between the mares, the only stallion in the room utterly left out. He was tempted to try and listen in but something about the conversation struck him as private so he just settled back into the bed, staring up at the ceiling and waiting.

“Are you sure?” Cadence asked excitedly, a hoof having strayed to Twilight’s cum belly where it slowly circled.

Twilight blushed, her own hoof having gone to Cadence’s much larger belly. “I know it's spur of the moment but it felt so… right.”

Cadence’s grin grew from ear to ear. “Can you cast it on me first? I want to cast it on you.”

The purple alicorn nodded, casting the fecundity spell slowly, allowing the other alicorn to learn it relatively quickly. A few hushed questions later and Cadence was ready, her horn glowing brightly. The pink alicorn stowed her desire to grin like a mad filly, pouring a little more power into the spell then what it normally required before unleashing it on an unprepared Twilight.

Twilight shivered as the spell settled into her body, changing it to it's designs. In seconds she felt oddly different, it wasn't something obvious that she could put her finger on she just felt ready, somehow.

Together the two mares shared a giggle before turning back to Shining Armor who was staring intently at the ceiling, counting the tiny glowing stars that had been stuck there for years.

“Ahem.” Cadence said hautighly.

Shining Armor blinked, looking at the two mares. “What's up?”

Cadence rolled her eye and twisted onto her side, exposing her winking marehood, her tail having been pushed out of the way. “I will beat Luna and Celestia in size but to do so I am going to need some help if your feeling up to it.”

“I’m always ready.” He said with a smile, his cock twitching as if on command.

Twilight blushed, watching as her brother stalked over to Cadence, eying up her form and slowly slipping into a better position. Cadence turned to Twilight just as the stallion seemed to get into position. “Now Twilight, I am going to give you some excellent tips on how to be a perfect wife.”

Twilight nodded, having to resist the urge to summon a pad of paper and something to write with. Noticing that her student, and her husband were both ready, she pushed her hips up, angling her body towards the Shining Armor’s throbbing erection. “Having a husband that is much smaller than you is not easy, but all it takes is a good knowledge of the positions to better fit your height difference like this.”

Shining Armor rolled his eyes and pushed forward slightly, brushing the tip of his cock over his wife’s hole. “May I continue, or do you have a lecture to give?”

Cadence tapped her chin as if carefully considering it before smirking. “Go head my love.”

The stallion shrugged, pushing his hips forward and inserting himself into the mare’s hole with such relative ease that a single smooth thrust nearly had him bottom out in a matter of seconds.

Cadence sighed, running a hoof down her belly. “Remembering the things he likes is key to the entire process, such as moaning his name- oh Shining Armor- and telling him how big he is.” She turned to her husband. “Your so big my love!”

Shining Armor stifled a chuckle and slowly pushed his cock a little deeper, allowing a few more inches to slip inside.

“A good wife is always ready to accept her husband’s cock and as such she must be perfectly stretched to the size of his cock, allowing him to slide right in.” She nodded to her stallion who thrust his hips forward, burying himself in her cunt.

Cadence’s eyes went wide as the last inch slipped inside her. “It seems like someone grew another inch.” She smirked and turned back to Twilight. “Always be ready for a surprise like that. Sometimes your hubby gets bigger or smaller depending on a lot of things but more on that later.”

The stallion settled into a slow rhythm, dragging his hips back and forth as he fucked his wife while his sister watched closely.

“Learn the shape and feel of his cock.” Cadence purred, her pussy gripping and milking the stallion’s shaft with practiced ease. “This makes it feel better for the stallion, and for yourself.”

Taking a nod as his cue to speed up, Shining did just that, thrusting a little faster, but not so fast as to potentially disrupt Cadence’s little lesson.

“Enjoy the feeling of his cock nearing your womb, it means he's almost ready to put a baby inside you.” Cadence pointed out.

Shining Armor grinned and sped up even more, making the slight tremor in Cadence’s belly to grow until a sloshing motion that was audible over their moans. The alicorn next to them licked her lips at the sight, her gaze fixated on the other mare’s much larger belly.

“It also feels amazing to have somepony’s lips on my aching nipples, but due to the position, a third party could stand in for your hubby.” Cadence said with a smirk, parting her legs slightly and letting her large, full breasts to flop down onto the bed.

Twilight giggled before moving down between the other mare’s legs, taking nipple into her mouth and gently beginning to suck.

Cadence moaned aloud, her hoof gripping the bed sheet tightly as she rode the waves of pleasure rocking through her. “S-sometimes everything feels just perfect so you are alright with moving a little faster than usual.”

Shining grunted his ascent, his hips now moving at a blinding pace as he fucked his wife hard and deep.

Twilight shifted from one nipple to the other, unable to hear anything save for the slap of her brother’s nuts and the sound of Cadence’s belly sloshing audibly as the cum swirled inside her. A hoof snaked between the alicorn’s legs and she began to vigorously attack her love button as her other hoof rested on Cadence’s stomach.

The married couple knew all the signals, knew that they were both ready and willing to jump to the end of their little love making sooner rather than later. As such Shining Armor unleashed on Cadence’s pussy, throwing his weight into every thrust and using everything he had to ravage his wife’s pussy. Giving Twilight a front row seat to the action and giving her quite the full sensory experience.

It was clear to the alicorn that they both wanted the same thing, and were eager to get to it, meaning it took only a matter of minutes before Twilight could start to see the tell tale signs of Shining Armor’s orgasm coming on. His hips

“T-these h-hectic sessions are a little more fast paced but that's okay. Sometimes -unf- you are busy or you both want the same thing.” Cadence bit her lip before looking down at Twilight. “Though it would be nice to share a kiss with somepony new for a change.”

Shining Armor smirked. “Go on Twily, kiss her.”

Twilight blushed nervously, shuffling up the bed and embracing the pink alicorn. Their forelegs intertwined as did their passion and in no time at all Twilight found herself lost in the other mare’s embrace. There was something about the way she held her, the way she was able to pay attention to Twilight’s needs even as her own orgasm was coming on that made Twilight envious of Cadence.

A sudden intake of breath drew Twilight’s attention upwards, signalling that Shining Armor was ready to cum at any second. Sure enough a couple thrusts later he threw himself forward with more force then usual, burying himself completely before his cock erupted in cum. Neither pony had to tell the other they were close, they knew instinctively so when the stallion began to cum, Cadence did as well.

They continued to kiss unabated by the pair’s orgasms, even while Twilight felt Cadence’s belly distend, filling with even more cum they did not break. Until finally they were both done, and Shining Armor pulled out, his semi erect cock flopping to the bed a second before he did. The kiss lingered a second longer before Cadence pulled back and sighed contently.

“That was amazing.” She remarked.

Twilight nodded, running a hoof over Cadence’s belly. “You were.”

The pink alicorn smiled softly. “I have one last tip for you Twilight.” The purple alicorn perked up. “Sometimes one mare just isn't enough, so knowing when to share him with someone else is important.” Cadence’s hoof ran across Twilight’s comparatively smaller stomach. “Someone who needs plenty more cum in her.”

Twilight’s blush doubled in size and she looked up at Shining Armor expectantly, hardly noticing him as he trotted over to her.

Shining nods once. “And with that husband’s permission, another mare could be brought on. If she wants to be.”

“Yes!” Twilight yelled.

“Are you sure your ready for this, Twilight?” Shining Armor asked knowingly.

“Heck yeah I am!”

Cadence shook her head, her hoof circling Twilight’s distended belly slowly. “You aren't, but by the end of the night, you will be.”

Shining Armor sighed contently, glancing to his left where his wife snuggled contently onto that side of his body, her belly having grown large enough that she may have difficulty walking. Twilight on the other hand…

The stallion turned to his other side where Twilight lay snuggled close to his right. Though she wasn't quite as big as Cadence, only growing to appearing pregnant and ready to burst with triplets, she was still quite large.

The purple alicorn shivered unexpectedly, snuggling a little closer.

Shining Armor grinned, using his magic to gently pull the blanket a little higher, a massive smile spread across his face.

Finally, he felt complete.

Author's Note

Want to see stories like this before anyone else and get access to secret patron only stories, early releases for patreon supporters aaand other goodies? Drop just three bucks on my patreon and join the early release club!

Join me over on patreon and get instant access to exclusive content and early looks at new stories, patreon only stories and other great stuff! Check it out!
Or just join the discord to ensure that you dont miss an update.
This update was made possible by the wonderful support of:
Apollyon6024
BooperDooper
DioKyo!
Facinus
Iamunknown
LuckyfanIsaac
M
Michael
Random Reader
Starless
T Sparkle