Derpy Stands Out

by AzureDreamer

Rating: mature
Tags: Slice of Life, Alternate Universe, Anthro, Porn, My Little Pony: Friendship is Magic, Fetish, Starlight Glimmer, Adventure, Derpy Hooves, Sex
Length: 12432

Derpy is sent on the quest to deal with Starlight's town. Bigness ensues.

Princess Twilight's friendship table has spoken, and Derpy finds herself sent to a mysterious town in the middle of nowhere to solve a nebulous friendship problem, much to her consternation. It's out of the way, and everyone seems off. They all kinda talk the same and wear the same clothes and act the same and even look the same - which makes Derpy and her colossal breasts stand out all the more. Which, it turns out, is not exactly a welcome trait in this town, something that the Mayor intends to drive home whether Derpy likes it or not.

Unfortunately for Starlight, she might have grossly underestimated what she's up against.

WARNING! CONTAINS ANTHROS, FUTA, BREAST EXPANSION, LACTATION, EXTREME HYPER BREASTS, BREASTFEEDING, GROWTH, MACRO, AND PROBABLY A BUNCH OF OTHER WEIRD STUFF

cover art by Hyperstorm_h.

Commissioned by Nimnul.

Consider donating to my patreon to fund more stories like this!

Published 2022-05-06 21:20:02 UTC
Last updated 2022-05-06 21:20:02 UTC

Equality (or something to that effect)

Derpy was not entirely sure why she was where she was. It kind of felt like the universe itself was out to get her, in this particular situation. She didn’t really want to be here – she’d never exactly been one for travel, and getting here had taken a significant amount of travel. Here she was, in the middle of fucking nowhere, miles away from her home and her daughter,in a town so small that she was pretty sure it didn’t even have a name. And for what? Princess Twilight had pointedly neglected to actually tell her that.

“Here’s the deal. I’ve got this magic map, it says there’s a village somewhere that has a problem or something.”

“Okay?”

“And it also says that the solution is to send you there.”

“What.”

Twilight shrugged. “Yeah. I know. Look, if it helps, think of it as a vacation.”

“I don’t like vacations.”

“Everyone likes vacations, Derpy.”

“When I take time off I want to actually take time off. Not spend all my time working out the logistics of going somewhere far away from the creature comforts of home and then figuring out things to do while there that aren’t things I could just do here and then doing those things which means I don’t get any actual fucking relaxation in.” Derpy crossed her arms, an impressive feat given her proportions. “Vacations are stressful.”

“... Yeah, I can understand that.” Twilight seemed legitimately sympathetic, at least. Not sympathetic enough that Derpy wasn’t still forced to participate, of course. But at least Twilight felt kinda bad about it.

Part of the problem was that, now she was here, Derpy had absolutely no fucking idea what to do next. Twilight had been no fucking help on that front, of course. “All I know is that it wants you to go here. There’s no indication of what it actually wants you to do when you get there.” She shrugged again. “Maybe just try asking around about if anyone has any friendship problems?”

Derpy tried doing that. It didn’t work. Though just saying it didn’t work didn’t really quite do justice to the whole situation. She had, at least, gotten a bit of a grasp on what might potentially be going on. Everyone seemed happy. Too happy. Like, happy enough that Pinkie Pie would tell them to maybe take a chill pill or two. And beyond that, they all, for the most part, talked the same. Not completely identical, but the same general word choices to say the same things. Similarly, they all kinda looked the same, too. There were unicorns and earth ponies and pegasi, sure, and they all had different clothes and hair and such. But that didn’t do a great job of hiding the fact that they were all around the same height and had around the same build.

But the real clincher that something was up was the fact that, though their modest clothing meant it wasn’t immediately obvious, they all had the same cutie mark – a pair of thick horizontal black lines, like an equals mark. That was weird. Beyond weird, even. Unheard of. There were, of course, plenty of ponies with similar cutie marks. And, given the sheer overwhelming volume of ponies who had ever lived, statistically there were even probably ponies with the exact same cutie marks on occasion. But every single person in a town, even a small one, having completely identical cutie marks? And especially something so... bland. Twilight was right; there was definitely something up with this town.

Unfortunately for Derpy, the fact that everyone was the same made her stand out even more than she usually did. And, to be frank, Derpy by default stood out a lot. Because her breasts were gigantic and constantly leaky. To the point where she basically had to exclusively wear swimwear – anything else would get soaked through in a heartbeat even at the best of times. She wasn’t the only big girl in Ponyville, of course, but she was definitely one of the biggest.

But here she outright was the only big girl. Everyone else had normal figures, or even outright sub-normal figures,and here was this bikini-clad hyper-endowed milky bombshell wandering around town asking if they had any friendship problems. It was no wonder that eventually they quietly and awkwardly herded her into the mayor’s office – honestly she was surprised they didn’t do it sooner.

“First off, let me just... apologize for the inconvenience.”

“I can probably find clothing that fits, if that’d help.”

“No, no! It’s fine! You’re a guest in our town, it would be unreasonable for us to demand you follow our social norms. At least, not if you have no intention of staying long-term.” The mayor, a pinkish unicorn with a dark purple mane that had a blue stripe running through it, smiled warmly. Maybe a bit too warmly, though it oddly didn’t stand out as much as everyone else in town’s smiles. Which in turn made it even more shady than the creepy fake too-enthusiastic smiles everyone else had. “I just thought that since you had so many questions, I might as well answer you directly.”

“Thanks for that.”

“Ah, but where are my manners. My name is Starlight Glimmer, it’s a pleasure to meet you.”

“Likewise.” Starlight smiled expectantly at Derpy for what felt like minutes. She pointedly didn’t actually ask the obvious question, instead waiting for Derpy to quietly sigh and give her name unprompted. “Derpy Hooves.”

“Welcome to our town, Miss Hooves.” Starlight smiled ominously. Well, okay, she smiled. Any degree of ominousness was up to personal interpretation. Derpy chose to interpret it as ominous, mostly because the whole town gave off a vibe, and Starlight in particular was very... cult leader-y, to put it nicely. But beyond the context, Starlight’s smile was still very normal and natural. If she was up to something, she was doing a good job of seeming happy and friendly, if not that she wasn’t up to something. “Now, to business. You had questions? I have answers!”

“Okay so my first question is what the fuck.”

“Hey, now, mind your language.”

“Sorry.” Derpy wasn’t actually particularly sorry – she’d always hated people who bitched about swear words. But she was also smart enough to know that it was a bad idea to intentionally antagonize Starlight before getting the information she needed. So for now she was going to pander to her. “So it’s kind of a long story and I doubt you’ll believe it but the short version is that there’s a magic map that says there’s some sorta problem going on here and the solution is to send me. That’s all I’ve got.”

“Well, I can’t fathom what possibly might constitute a problem! We’re all happy here, as I’m sure you’ve seen.”

“Yeah, everyone’s definitely all smiles,” Derpy replied. “Like, all smiles. No frowns, not even a neutral expression as far as I can tell.”

“Well, we’re all happy here.”

“You just said that.”

“And I’ll keep saying it as many times as I need to to get the point across.”

“Okay. I just find it all a bit... suspicious, you know?”

“Suspicious?”

“Everyone all talks the same and they’re all built the same. The exact same figure.”

“I think you’d be surprised how normal that is. You, ah, seem to be something of an outlier. That might have skewed your perception, perhaps?”

“That’s why it stands out to me, though,” Derpy shot back nonchalantly. “Normally I barely even register that somepony’s smaller than me because basically everyone’s smaller than me.”

“And?”

“It’s not just that everyone here’s small. It’s that they’re all exactly as small as each other. No variation whatsoever.”

“I would argue that’s better, no?”

“How so?”

“Everyone here is equal. No one feels inadequate as a result of being exceptionally small, and no one has to deal with unwanted attention from being exceptionally big.”

“I like unwanted attention.”

“I’m sure you do.” Ah, there we go. The mask had started to slip, if only a little. Just a little glimpse of cattiness behind the obvious affectation of small town niceness. “We tend to be more, ah, modest here. Certainly no one is going around wearing skimpy bikinis that barely cover their nipples, regardless of how well endowed they are.”

“Oh, the bikini’s not about showing off,” Derpy retorted.

“... It’s not?”

“Nope! See, I used to be pretty normal before I got pregnant. And, well, I imagine you know how pregnancy works. They got bigger and milkier. That much is normal, what’s interesting is that they just kept right on growing! And of course they got leakier, too. So all my clothing has to be waterproof.”

“Oh.”

“Oh, yes, to say nothing of the fact that intimacy made the milk production kick into high gear. So they got even more milky. And bigger, too.”

“Why are you talking in past tense.”

Derpy stood up, looming over Starlight’s desk and leaving her tits almost perfectly eye-level with the still-sitting pony. “Oh, well, a few years back there was an Incident.”

“Incident?”

“I won’t bore you with the details, all you know is that a friend wanted to do some tests to see if she could figure out why they do that and things went off the rails.”

“So they... don’t grow anymore?”

“Oh, no, they still grow. If anything, they grow even more than they did before! But the real big difference is that now if a pony drinks my milk they grow, too!”

“Oh.”

Derpy smirked smugly. There was nothing she loved more than expositing about her breasts. And, more specifically, this right here was her favourite part of expositing about her breasts. “Wanna experience that bit first hand?”

“Oh. Um. No, thank you.”

“I insist,” Derpy replied, lurching forward and burying Starlight’s torso in her cleavage.

“Mph!” Starlight immediately placed her hands on Derpy’s tits in a futile attempt to push the much larger pegasus off of her. It was very easy to underestimate Derpy – her boobs drew all the attention, so people often didn’t notice that the rest of her was pretty big too. She was a good foot taller than Starlight. And, where Starlight was thin and willowy and very much the perfectly average unicorn, Derpy was buff. Pegasi already had naturally good upper body strength anyway. Between that, the fact that her job as a mailmare meant that she spent a lot of her time flying, and hauling around her massive milk jugs all the time, Starlight had zero chance of overpowering her.

“Oh, don’t worry! I’ve got plenty of milk to go around, especially once I get going. So there’ll be no uneven distribution or anything, everyone will be as equal as they wanna be!” Okay, yes, maybe she was being a bit insufferably smug, but Starlight seemed like she fucking deserved it. She placed her hands on Starlight’s and pressed them deeper into titflesh.

“Get offa me!” Starlight tried to say, but it was almost completely muffled by cleavage.

“Sorry, I didn’t hear you, could you repeat that?”

“Get the fuck off of me!”

“Hey, now, mind your language~”

That, it seemed, was the final straw for Starlight. Her horn, or what of it was visible, was enveloped in a pale lilac glow before there was a bright flash of light and a sharp noise and suddenly Derpy found herself somewhere completely different. A big, stone cave, somewhere deep underground. Somewhat more concerning was the big wall-sized shelf filled with glass jars containing floating cutie marks and the conspicuously floating wooden staff. “Ah. Well, I think I’ve found the problem I’m supposed to solve.”

“I was hoping that I could just feed you some bullshit story and you’d go away. Obviously that was naive of me, so we’re just skipping straight to magically enforced equality.”

“Ah yeah okay. That’s the direction we’re goin’ with this, then?”

“Yes.”

“I wouldn’t if I were you.”

“Unless you agree to stop rocking the boat, leave quietly, never come back and never tell anyone about this place? No, this isn’t an option.”

“Fair enough. I can guarantee you it’s gonna go poorly tho.”

“I think you’re underestimating me.”

“I think you’re underestimating my tits.”

“Hmph. We’ll see who’s underestimating who.” Starlight made her way over to the aforementioned conspicuously floating staff. It was long and thin, twisting and twirling along its length before splitting into two prongs at the top. “This is the Staff of Sameness.”

“It kind of looks like a weird stick you found on the ground.”

“It is not a weird stick I found on the ground. It’s a powerful magical artefact used by the legendary Mage Meadowbrook.”

“I have no idea who that is.”

“Of course you don’t,” Starlight said, rolling her eyes and grabbing the staff.

“And it still looks like a weird stick you found on the ground.”

“Let’s see if you still think that after I unleash its power on you.” She twirled the staff in her hands before directing the two prongs at Derpy. “The Staff of Sameness has the power to render ponies completely and utterly equal in every aspect.”

“Okay cool. I guess that answers most of my questions then.”

“And now I’m gonna use it on you.”

“Go for it!” Derpy replied with a shrug.

“You’re being far too blasé about this!” Starlight brandished the staff about as threateningly as one could brandish a weird stick. “Your cutie mark, your special talent, everything about you that makes you ‘unique’ is going to be gone forever!”

“If you’re so confident about that, then why haven’t you zapped me yet?”

“Fine, I will!” Starlight brandished the stick again, both it and her horn quickly becoming enveloped in a pale blue glow. Something clicked into place in Derpy’s mind, although she elected not to say anything about it just yet. Instead she just sat there and watched passively as the glow shot out of the staff in the form of a beam that struck her directly in the upper thigh.

Derpy had expected it to hurt, at least a little. She wasn’t really sure why, because it wasn’t like she had any experience with having her cutie mark removed. It just made sense that it wouldn’t be painless, she supposed. But it turned out that her instincts were wrong about that. It just tingled a bit, and frankly if she couldn’t literally see her cutie mark floating off in a bubble of blue light she might not have even noticed something happened. Or at least not at first. Mentally she didn’t feel all that different. Maybe a bit tired. She imagined that she’d notice if she tried to do anything relating to her special talent? But for now she wasn’t, and so the most obvious sign that something had happened was the noise. It took her a moment to put her hoof on it but once she did she was surprised that she didn’t realize it sooner because it was so obviously the sound of a balloon slowly deflating.

And, at the same time, her curves also deflated. It was a weirdly familiar feeling – you wouldn’t think that Derpy would be used to her boobs getting smaller but you’d think wrong. Yes, her boobs were constantly growing. And their default resting size had definitely gone noticeably up over the past few years. But the thing a lot of people forgot was that every single time she got involved in Shenanigans that resulted in breasts the size of a small town, they had to shrink back down afterwards. Granted, usually when that happened they were much bigger and were honestly still unreasonably large when they finished.

It turned out, though, that shrinking down from the size of a building to only the size of overinflated beach balls wasn’t actually all that different from going from beach balls to nothing. She was more interested in her lower body – she had a lot less experience with any kind of size-changing going on with her hips and butt. Given the sheer raw magnitude of her tits, it was easy to forget about that half of her body. But just because she was top-heavy didn’t mean she didn’t have a nice ass. It was a kind of weird sensation, and she didn’t care for how it resulted in her bottom just sort of sliding off completely, laying uselessly on the ground. But, on the other hoof, she was extremely interested in seeing how it felt when she inevitably grew back to normal. Ass expansion was new and uncharted territory for her! Fuck, she was pretty sure she even got a few inches shorter. She actually did have some experience with size stuff – there had been an incident with some Changelings a few months back. Sadly, this wasn’t nearly as extreme a change as the others, but it was still fun.

“Ha!” Starlight said with a smug smirk on her face. “I told you not to underestimate me.” She made a gesture with her head, and Derpy’s cutie mark floated into a jar which quickly closed itself.

“Yeah, sure,” Derpy replied, still thoroughly unimpressed. She idly toyed with her bikini top, which hung loosely over her torso. It was kinda funny how not thirty seconds ago it had been almost too small but now it was like she was wearing a fucking circus tent.

“You put so much stock into your size, but now you’re the same as everyone else. Don’t worry, you’ll come to appreciate equality soon enough. Everypony does eventually.”

“Nah.”

Starlight’s smug smirk faltered, just a little bit, for only a second. “Hmph. You’re going to have to get used to it because they’re never coming back.”

“Give it ten seconds.”

This time, Starlight’s smirk slowly morphed into a confused frown. “What do you mean?”

“Five, four, three, two-”

Fwoomph.

“what”

“Oh, ahead of schedule!”

If you didn’t know that Derpy had just spent a minute or so with her size drained, you probably would not guess that to be the case just by looking at her. Her bra was askew, and obviously her bottom was still on the ground, but otherwise she looked just about unchanged. Much to Starlight’s obvious visible consternation. “Wh- how?”

“I told you not to underestimate my tits.”

“What does that mean.”

“Like, come on. Do you seriously think I never once tried using magical solutions to make my tits more manageable?”

Starlight frowned – as though she’d not been frowning for most of this entire fucking conversation. But it was a subtly different kind of frown. “I didn’t take you for the type.”

“Well, yeah, not anymore. But when all this first happened I kind of felt the need to be able to, yanno, fit through doors? So I tried pretty much everything short of breast reduction surgery and nothing would stick and it wasn’t quite a big enough problem to justify actually going under the knife. So I just sort of decided I’d deal with it and eventually I came to appreciate the inconvenience.”

“I see.”

“You might even say that they grew on me.” Derpy chuckled at her own joke while Starlight’s frown deepened. “And this was before the incident, so really who knows what kind of effect this’ll have in the long term?”

“Hmph.” Starlight steeled herself, once again pointing the weird stick at Derpy. “Clearly that was a fluke!”

“Keep tellin’ yourself that.”

Starlight didn’t rise to the bait. Instead, she just did the thing once again. Beam of light, directly to her chest, and once again the sound of deflating balloons echoed throughout the cavern. Slowly, Derpy found herself shrinking down once again. “All I have to do is keep on trying until it sticks. Simple as that.”

“I don’t know, that seems like it’s just asking for trouble.”

“I will make you equal if it kills me.”

“Okay so like please don’t actually take things that far. It’s not fun anymore if you die.”

Starlight rolled her eyes. “It’s a figure of speech.”

“With all due respect, you don’t strike me as the figure of speech type.”

“Hmph.” Starlight, once again, didn’t dignify Derpy with a response, instead changing the subject. “Anyway, it’s been longer this time. Clearly you were wrong.”

“Give it another second or so.”

“You can give it as many seconds as you wish. Like I said, it was merely a fluke that it didn’t work last ti-”

Fwoomph.

“Oh come on!”

“Toldja.” Once again, it was almost like nothing had happened. Almost –Derpy’s bikini top was even more dishevelled than the last time, with the straps misaligned and digging into soft, grey-furred expanses of flesh. “Huh, y’know what? I think I might actually be bigger.”

“Don’t even joke about that!!!!!”

“I’m not joking.” Of course, Derpy had actually been joking. Intentionally trying to get under Starlight’s skin. But, as shehefted her tits from below she found herself starting to think that maybe she had been right. “Look, this bikini is brand new, it should still at least kinda fit? I think I might be a bit taller, too? Like, when we started I was a foot or so taller than you then you zapped me and made me the same height as you and now that I’ve grown back it looks to be more like a foot and a half taller.”

“Stop playing with your fucking tits!”

Derpy did not stop playing with her fucking tits – though, to be fair, she wasn’t really playing with them. She was actually attempting to adjust her top so it at all covered her nipples, which was especially necessary now that the straps digging in and pressing against them had resulted in some increased leakage. And, since somepony had made it clear she wasn’t gonna be helping on that front, Derpy was just going to have to deal with it. “Speaking of which, could we maybe drop this whole thing? I like my tits getting bigger as much as the next mare but they’re clearly not going anywhere and I did just buy this top.”

“No I will not drop this!”

“Suit yourself.”

“Hmph. Last time it stuck for longer, so obviously the problem is that I’m not using enough power.”

“Okay cool.” Derpy rolled her eyes. Best to just let her get it out of her system.

“Enough talk! I’ll just have to give it everything I have!”

“Hey, don’t hurt yourself, okay?”

“I already told you not to underestimate me,” Starlight replied with a smirk, once again pointing the weird stick Derpy-wards. “I’ll have you know that my special talent is magic.”

“I thought you didn’t have a special talent?” Derpy said, knowing full well that Starlight had absolutely been faking it the whole time. She’d not done a great job of hiding it.

“Hmph.” Yeah, she’d hit the nail on the head. Probably no one else in town had figured it out, but Derpy had enough experience with high-end magic users to immediately recognize a high-end magic user. But Starlight wasn’t going to give up the act quite so easily. Instead, she silently pointed the stick at Derpy, both it and her horn enveloped in a bright glow – one that quickly grew brighter and brighter until it was almost blinding. “I will make you conform.”

“Impressive light show, at least.”

“It’s not just a light show!” Starlight snapped before firing the beam once again. This time, though, instead of just a single blast, it was a steady stream of magic. “If one blast isn’t enough, then I’ll just keep on draining you until it stops coming back!”

“Wait hold on, draining?”

“Shut up!”

Derpy mostly ignored the shrinking this time. She had other concerns. “No, seriously, if you’re draining my size rather than just shrinking me then that implies that it’s going somewhere, right?”

“I said shut up!!!”

“No seriously this suddenly sounds like a recipe to get someone hur-” Fwoomph.

“Argh!!!!” Derpy regrowing while being drained only seemed to push Starlight even further over the edge.

“I really think that you should maybe slow down a bit.”

“Not until you conform!”

“I’m serious, this-” Fwoomph. “This is almost certainly going to end badly.”

Of course, there wasn’t much point in trying to reason with Starlight because the unicorn had absolutely tuned out everything else. She was completely and utterly focused on de-bigging Derpy. She wasn’t even verbal at this point, just making loud angry noises. There probably wasn’t any point in trying to reason with her, but Derpy felt like she should at least try and talk her down. “Okay so-”

“Shut up!”

Fwoomph.

Well okay never mind that then. “Look, I’m an innocent bystander in all of this. I don’t care if you’ve got some kinda crazed, single-minded obsession with equality but like could you not drag me into it? That’s all I ask.” No response from Starlight beyond some more wordless rage and another fwoomph. “How long is this even gonna go on?”

“You know exactly how long it’s going to go on!”

Fwoomph.

“... You know what, I’m just gonna leave now, okay?”

“No you’re not!”

“I mean... Is there anything stopping me from just sort of leaving?”

Fwoomph. No response.

“Because this is kind of getting old and so if there isn’t anything stopping me from leaving then-”

“I’m stopping you from leaving!”

“Okay, okay.” Derpy decided not to push things farther in that direction. She was pretty sure that, if she wanted, Starlight could absolutely use some sort of unicorn magic to hold her in place. And she really didn’t want to see how that interacted with the spell she was already casting. This whole situation was already a recipe for disaster as it was without actively tempting fate.

That being said, she supposed that she couldn’t deny there was a noticeable effect. The time between the fwoomphs was definitely getting longer and longer, and the magnitude of the fwoomphs was less – though Derpy was fairly sure that was more the result of the constant presence of Starlight’s magic shrink ray. Still, she was undeniably staying smaller for longer. Whether or not that was actually a sign that Starlight’s magic was working or just foreshadowing of impending doom was another thing entirely. Of course, on the other hoof, she wasn’t going to actually raise that question out loud. Right now the best case scenario was for Starlight to think that she’d won because that meant she might let Derpy go.

Derpy wasn’t really sure how long Starlight actually kept it up. There obviously wasn’t any kind of clock in the cave, and it was so uneventful that after a while it all just sort of blended together. Eventually Starlight ran out of juice. The beam of light stopped and she collapsed forward onto her knees, using the stick to keep from outright falling onto her face and breathing heavily. Still, in spite of her clear and visible exhaustion, she had a big smirk on her face. “I win.”

“Uh huh. Right. Sure. Do you need a hand getting up or-”

“I can handle myself!”

“Fine, fine.” Once again, Derpy couldn’t help but roll her eyes.

“Anyway, now you may leave,” Starlight said, in between laboured breathing. “Go forth, mingle in our town, and learn just how much happier you’re going to be now that you’re truly equal.”

“I mean, I’m equal for now.”

“And forever.”

“I’m gonna fwoomph any minute now.”

“Ha! That’s where you’re wrong!” Slowly Starlight pulled herself upright, using the stick as a crutch. “For you see, I didn’t just drain your size-”

“Yeah see again, I gotta ask the question of where you drained it to.”

“I’m getting to that,” Starlight responded huffily. “You see, obviously my standard measures weren’t going to cut it. So instead of merely draining your size, I also located what I believe to be the source of your constant growth and inserted a magical blockage!”

“what”

Starlight’s smug aura intensified, not quite realizing that Derpy wasn’t actually asking for clarification. “Think of it like this; imagine you’ve got a sink that leaks. The obvious cause is that a valve somewhere is looser than it should be, and so you fix it by finding that valve and tightening it. I did the same to you by blocking off a magic conduit that should have been shut.”

“What.”

“No need to thank me.”

“Why would I thank you?! That’s not tightening a valve, that’s stuffing a bunch of rags into the spout and then turning the water on to full blast!”

“Hmph. I’ll have you know that my solution was much more elegant than that.”

“Oh my god that’s absolutely not the point.” Derpy pressed her hands on her temples. “Do you even know anything about plumbing?”

“That was just a metaphor. I imagine you don’t know as much about unicorn magic as I do, so I simplified it significantly.”

“Okay but if it was even slightly apt as a metaphor then we should really get out of the cave now.”

“If you want to leave, I won’t stop you. I’ve already won, after...” Starlight trailed off, her smug smirk once again shifting to a confused frown. “What on earth is that noise?”

It was hard to put the noise into words. A deep, distant rumbling noise. Kind of like an earthquake, crossed with an angry animal growling, crossed with a waterfall. Getting louder and louder with every passing second. And, as it got louder, it also became clear that the sound was coming from Derpy.

“... I should probably get outside. Now.”

“I think I have enough juice left to get us outside of city limits.”

“That’s a good idea.”

There was a flash of lavender light, and in short order Derpy found herself and Starlight standing on some sort of mountain road. A cold wind blew through, reminding Derpy very thoroughly that she was still in fact very naked. “Couldja maybe have picked somewhere warmer?”

“Look, this is as far away from town as I could get us. Would you perhaps rather still be in the fucking cave?”

Derpy frowned, thinking back to the last time she’d gotten involved in growy shenanigans in a cave. “Fine, fair enough. But couldja at least cast, like, a warmth spell or something?” Normally Derpy’s bikinis were enchanted to keep her more warm than normal, but obviously that was predicated on Derpy wearing her bikini. Right now the bottom was still in the cave and the top only counted as worn in the loosest, most technical sense.

“No,” Starlight grumbled in response. “I couldn’t cast even the simplest cantrip at this point.”

Derpy was still annoyed, but she supposed that it was believable enough that Starlight was completely drained at this point. She certainly looked it, with the way she was leaning even more heavily on the Staff of Sameness than she had been. “Did you seriously bring that fucking thing along?”

“The Staff of Sameness is an extremely powerful magical artefact.”

“It’s a weird stick you found on the ground.”

“It’s not a weird stick I found on the ground,” Starlight replied, though with significantly less indignation than her earlier denials. Going by her facial expression, even she was aware that no one was buying it anymore, but she just didn’t have the energy to keep up the facade. “Anyway, hurry up and... do the fuckin’ fwoomph thing.”

“I would love to,” Derpy said snidely, crossing her arms underneath her breasts – a much less logistically complicated feat than normal. “But someone decided to stuff some rags in my magic milk valve.”

“Would you please stop getting so hung up on the specific wording of the metaphor I chose to use? Everything’s probably going to be fine.”

“I’m making earthquake noises.”

“Everything’s probably going to be fine,” Starlight repeated, more firmly.

“You remind me a lot of Twilight, you know?”

“Oh, the Princess? I-”

“Remember that incident I mentioned? Literally entirely Twilight’s fault.”

“oh,” Starlight replied simply, deflating as she realized that the comparison wasn’t a compliment. “A-anyway,” she continued, unsubtly changing the subject. “Obviously if anything was going to happen, it would have happened by now.”

“Right, tell that to the earthquake noises. Did I mention the earthquake noises? Because the earthquake noises are kind of concerning.”

“Forget about the earthquake noises!”

“And you still haven’t explained where you drained all the size to, by the way.”

“The staff of sameness, obviously.”

“Oh boy.” Derpy pinched the bridge of her snout. “Okay so like I don’t actually know enough about magic to say for sure? But there’s nothing you can do to convince me that you can store all that size in a weird stick you found on the ground.”

“Enough with the weird stick thing!” Starlight seemed to have recovered at least a little of her energy, as she made an attempt at flailing around indignantly. It wasn’t a successful attempt, mind, and it almost ended with her falling on her face and dropping the stick.

“Hey, careful with that thing,” Derpy said, taking a few steps back. “I don’t know what’ll happen if you break it, but I can’t imagine it being anything good.”

“It’s a powerful magical artefact. It would take a lot more than just treating it slightly carelessly for it to break.”

“Okay see now that you say that, you know it’s going to break like immediately, right?”

“It’s going to be fine,” Starlight repeated.

“I’m just saying that it can’t hurt to be careful.”

“I would have to literally try to break it, it’s fine.”

“Please stop tempting fate.”

“I’m not tempting fate,” Starlight replied, giving Derpy a surly glare as she slowly pulled herself upright. “Look, I’ll prove it to you.”

“Please don’t. I actively want you to not prove it to me.” Of course, Derpy knew that Starlight wasn’t going to listen to her. Listening to reason didn’t exactly seem to be in her skillset.

“I’m going to prove it.”

“For fuck’s sake.”

Starlight, predictably, ignored Derpy’s exasperated response as she grabbed the two prongs and leaned forward, placing most of her weight onto the stick. “See? It’s perfectly fine.”

Equally predictably, one of the prongs fucking snapped right off immediately after she said that. “Shit!”

Somewhat unsurprisingly, a lot of things happened at once in very quick succession. Starlight, the thing she was putting all her weight on having suddenly snapped into pieces, immediately fell forward, landing on top of the remains of the stick. Which, of course, fucking exploded in a flash of yellow. Bright enough that Derpy found herself temporarily blinded. Acting entirely on reflex, she moved her arm up to cover her eyes – almost exactly too late to actually be of any benefit.

“Don’t just stand there! Help me!”

“I would love to,” Derpy replied tersely. “But I can’t see.”

“I don’t care! Do something!”

“Remind me whose fault this is, again?”

“Yours!” Starlight snapped. “If you’d just left well enough alone then we wouldn’t be in this mess!”

“All you hadda do was just teleport me away, yanno. You didn’t have to do any of this.” She rubbed her eyes, blinking furiously in an attempt to clear her vision. Which worked, though very slowly. Vague blurs coalesced from the void. A vague grey shape that represented the mountainside, another brown shape that was probably the road, off to the side there was some green that were probably trees and a lot of blue that was probably sky.

But the biggest blurry blob of all was a purple one right where Starlight should be, coalescing into what probably wasn’t the funniest thing that Derpy had ever seen but was certainly in the top five, and definitely one of the most satisfying things she’d seen. Her hand moved from covering her eyes to covering her mouth as she made a token but also intentionally halfhearted effort to stifle her giggling.

“It isn’t funny! Help me up!” It was, actually, extremely funny. Derpy supposed she couldn’t blame Starlight for needing help because there was absolutely no way she was going to be able to stand up, for exactly the reasons Derpy had predicted. It seemed like, after the stick broke, all of that size Starlight drained from Derpy had to go somewhere. And the closest receptacle for all that size was, it turned out, Starlight Glimmer.

Starlight had not been a particularly big pony. Even ignoring the obviously unfair comparison that was Derpy Hooves, she was built like a unicorn. And unicorns, barring the occasional exception like Rarity or Lyra, trended towards being short and slender and elegant – and Starlight had fit that typical build to a tee. Which, really, given her obsession with conformity, it was extremely unsurprising that she herself was built like the perfectly average unicorn.

‘Was’ being the key term. Past-tense. Most of her bodymass was, of course, boob. An absurd amount of boob. Like, way more absurd than Derpy had expected – even factoring in the sheer amount of Derpytit that she had to have drained, they went well beyond that. And that wasn’t the only part of her that had grown more than expected. Derpy had expected her to be a few feet taller, possibly pushing into amazon territory. Instead, she was well into the point where she counted as a giantess. Everything about her was gigantic. Even if she was shrunk down to a normal height but everything else stayed proportionally the same, she’d still have tits that put Derpy to shame, muscles that would make Applejack look like a schlub, an ass that would make Pinkie Pie’s seem minuscule-

And, most interestingly, a big ol’ purple horsecock that would give Big Mac a case of clinical inadequacy. A flare bigger than Derpy was tall jutted proudly out between her tits, leaking copious precum.

“Stop laughing! It’s not funny!”

“On the contrary, I think it’s hilarious,” Derpy managed to say in between giggles. “Where did all of this even come from?”

“From the Staff of Sameness!”

“Okay but that’s way more than you could’a possibly drained from me.”

“Do you seriously think you’re the only pony I’ve equalized?! I’ve got the entire population of our town’s excess size in me and now I can’t fucking get up because my tits are too big!”

“Okay well I hate to break it to you but I’m way too small to make any kind of difference,” Derpy replied, finally calming down from her laughing fit. “Maybe if someone hadn’t blocked off my bigness valve I’d’a fwoomphed big enough to help by now.”

“Shut the fuck up and do something!”

“Well, you’re in luck! I do actually have something in mind that might help.”

“Good! I don’t care what, do it.”

“Okay!” Derpy strode forward confidently, standing in front of the massive, deep purple flare. “See, I’m thinking that it’s possible you didn’t just drain my size.”

“Uh-”

Derpy smirked. “You said you didn’t care what. So let’s see if stimulation does to you what it does to me.” She licked her lips eagerly before pressing her entire god damn body against Starlight’s cockhead. “And even if it doesn’t work, I’m enough of a size queen that I was always gonna end up playing with your cock regardless~”

“W-wait, hold on- Ah!” Whatever Starlight was going to say was interrupted by a copious gout of precum. An absolutely absurd volume, naturally. Derpy felt like she didn’t have to even acknowledge that fact, it was just assumed. Though, of course, the volume was so vast that it was impossible not to ignore. Especially considering that, y’know, she was pressing her body against the source of the precum. “H-how is this supposed to heeeeeelp?”

“I’d think it’d be obvious?”

“A-ahnnn~ I th-thought you said that – mnnnnn – th-that your condition was that your tits got b-biggerrrr~”

Derpy could guess where Starlight had been going with that train of thought, but she had very thoroughly derailed it by licking right by the urethra. “Yes, but there’s more to it than that. Making your boobs grow is just a pleasant side-effect.”

“Side effect of what?”

“You’ll seeeeee,” Derpy replied in a sing-song, shit-eating grin plastered on her face that Starlight absolutely couldn’t see.

She could probably appreciate the sentiment though, considering the hissed response of “ffffuuuuuck youuuuuuu.”

Derpy elected to ignore the indignant grumbling mixed with noises of arousal. She had higher priorities at the moment, mostly involving pushing Starlight to the absolute limit. The flow of precum was, at this point, almost constant. The larger pony’s meat throbbed in a regular rhythm, in time with translucent fluid oozing out all over Derpy. It tasted really good, of course. Salty and tangy, without the bitter tinge that cum typically had. Obviously Starlight had a very good diet. Or maybe it was just the result of weird magic shit, that was almost always a safe bet. Either was possible, though, obviously, this was kind of a unique situation and so Derpy couldn’t say anything for certain. She’d found herself stumbling into a lot of unique situations of late. Which was obnoxious, but at least it was generally fun in the end? Like, on the one hoof she would absolutely not say no to a little bit of a break from the nonstop barrage of sexy shenanigans. But on the other, if living in interesting times meant she got to hug a cockhead bigger than she was tall? Sign her the fuck up.

And especially sign her the fuck up if it meant getting to hug a cockhead bigger than she was tall that was growing. “A-ah! Stop that! This is the opposite of helpful!” Derpy, naturally, ignored her, continuing to apply stimulation. The fact that her dick was growing was probably a good sign that things were working as intended, but currently the priority was the boobs. Though that particular point seemed to not have penetrated Starlight’s skull yet. “I need to get smaller, not bigger!”

“Mnh. Getting smaller probably isn’t in the picture any time soon, lady.”

“Okay, fine! Suppose you’re right, how exactly does intentionally making the problem worse help matters?”

“Sounds like someone wasn’t paying attention when I explained my condition~”

“Wh-aaaaaahnnn~” Starlight’s repetitive confusion was interrupted by Derpy kneeling down and sloooooowly licking Starlight’s flare, from the ground all the way to her tippy toes.

That, it seemed, was enough to set Starlight tumbling over the edge of climax. Derpy quickly moved out of the line of fire as Starlight cried out and writhed on top of her waterbed tits, dick throbbing and pulsing and, eventually, erupting. Getting out of the way was clearly the correct decision, given the sheer force and volume – had Derpy stayed put, she would absolutely have been sent flying. This, of course, still wasn’t what Derpy was going for, but it was at least a sign that things were moving in the right direction.

Also a good sign was that her boobs were taking up noticeably more of the narrow mountain pathway. Thankfully not enough that she was in danger of falling off, or at least not yet. But it was only a matter of time before that became a problem, so Derpy had to work fast. “Which means, by the way, you need to stop holding back.”

“Mnahhhhnnnn~” Naturally, Starlight wasn’t exactly verbal. That was fine, Derpy didn’t really need her to be able to say anything. She just needed her to do the thing. The obvious step two in the process – first the boobs get bigger, then- “Ahn~”

“Ah! There we go!” White fluid flowed across the ground from underneath the massive fuckin’ beached whale of a pony. Lots of white fluid. It very quickly turned into an ankle-deep torrent of milk. “Honestly, if you’d let this happen sooner then we’d probably be done by now.”

Derpy got down onto her knees. “Normally I’d prefer to drink directly from the source? It can be a little overwhelming once things really get going, but it’s better than... you know. Drinking off a fucking dirt road? But obviously that’s not an option until after we flip you.”

Starlight made some vague noises that were probably attempts to ask why they needed milk. “I already explained this, if you didn’t pay attention then that’s on you,” Derpy said tersely, before cupping her hands and scooping up some of the liquid. “Hopefully it’s deep enough that there’s not any dirt in it...” she muttered to herself. She probably should have thought of that before deciding on this particular plan. But she’d committed, and anyway the only other plan she could think of was to just wait until that size-blockage Starlight had set up inevitably failed. Which like on the one hand having to sit there waiting because of her own dumb actions would serve the bitch right. But on the other hand, Derpy wasn’t nearly patient enough for that. And anyway Starlight’s current state was probably more than enough karmic retribution.

Derpy was, she realized, stalling. She did not want to drink the ground milk. Which was fair, most people would probably be reluctant to drink the ground milk. But she kind of needed to drink the ground milk. She’d already decided to drink the ground milk. The more she stalled, the worse drinking the ground milk would end up being. In the time that she’d spent bitching about drinking the ground milk, the scoop she’d taken had trickled out of her hands and back onto the ground. Dammit. She sighed, steeled herself, and then leaned down to drink directly off the ground like a fucking animal.

Thankfully, she ended up not getting a mouthful of dirt. Or at least not that she could tell. She decided not to think about that particular possibility because it was gross. Instead, she just focused on slurping up Starlight’s boob juice. It was kind of weird and kind of undignified, but at least it tasted good. It tingled slightly as it went down her throat, and settled heavily in her stomach. Was this what it felt like to be on the other end of things? Derpy wasn’t really sure if she liked it or not. Though she was fairly certain that once things got going it started to feel really good. It’s just that things weren’t going yet, and with the blockage she had no idea how long it would take for things to get going.

“What are you doooooing?” Starlight tried to say, though it quickly devolved into a moan. Derpy ignored her. Again; if she’d not paid attention to her earlier explanation of exactly how this whole thing worked, that was her own damn fault. She just focused on drinking as much milk as she could manage in the hopes that the nutrition factor was enough to overpower the stupid fucking magical growth inhibition spell that Starlight had stupidly cast.

“C’mon hurry up and work,” she muttered to herself in between gulps. Clearly, she’d underestimated just how stubborn Starlight’s spell was. But that was okay because Derpy was stubborner. If she weren’t then she probably wouldn’t be sucking up the ground milk. Honestly there was a part of her that kind of wished maybe she were a bit less stubborn because, again, drinking the ground milk was really not ideal. For now, all she could do was drink and wait. And drink. And wait.

It took her an upsetting amount of time to realize that, while she’d been absorbed in her internal monologue, the earthquake sounds had gotten louder. And were getting louder still. That was probably a good sign (or an ominous portent, depending on your attitude), and the other signs were also starting to get more pronounced. The tingling was more intense and the milk felt heavier. She could feel it flowing down her throat and into her stomach where it radiated heat out into the rest of her body. She felt tight and full, and getting tighter and fuller – and yet she couldn’t stop drinking. At some point one of her hands had wandered to press and rub against her moistening pussy with increasing vigour as that heat built and built, more and more and more until she couldn’t contain it anymore and then more than that.

Derpy decided it was probably best to stop drinking for now, as much as she didn’t want to. The fact that she wanted to keep going was another good sign that things were working as intended, though at this point she didn’t really need anymore signs. At this point she was absolutely certain that things were going as planned. She shifted herself to a kneeling position, one hand still working her puss while the other reached up to grope at what was left of her chest. Still flat, for now, but she could feel the heat concentrating there, along with her ass and cunt. “F-fuck,” she grunted as the pace of her masturbation picked up, faster and faster and faster until-

“Hic!”

Fwoomph.

“There we go!” Just like that, Derpy was once again back to her baseline – maybe even thicker, going by the earlier trend. Probably significantly so, when you factored in just how many times Starlight had de-fwoomphed her.

“How does that help?!” Starlight managed to say. Presumably she’d finished her climax at some point, Derpy didn’t know and didn’t care. She had other priorities.

“Oh, I’m not close to done.”

“Wh-”

“Hic!”

Fwoomph.

“what”

“Oh, that’s new!” Derpy’s boobs had remained proportionally the same, which was probably for the best because if they got much bigger she’d start having mobility issues herself. Besides, she was more than happy to get bigger in just about any way. Bigger boobs were obviously her favourite, but she wouldn’t say no to a bigger butt either. Or, as was the case this time, getting overall taller (significantly so) and buffer. She removed the hand that had been groping her tits and did a little flex, grinning eagerly. Normally she was deceptively buff, but as of now she was just regular buff. That was probably the milk’s influence.

Her other hand, meanwhile, remained firmly on her dick. That, obviously, was what was new. It wasn’t the first time she’d gotten bedicked, but it was still generally a rare occurrence. A nice little treat, especially after how her day had gone so far.

“Why did you grow a dick!?”

“That’s a good question!”

“That’s not a good answer!”

“I honestly don’t know,” Derpy replied with a shrug. “I’ve learned not to question any weird effects my milk might have. It just makes things more complicated.”

“That’s also not a good answer!”

“Sometimes my milk can be unpredictable. And I guess right now that means your milk can be unpredictable because you’ve gone and given yourself the same condition as me.”

“what.”

“I mean, physical stimulation made your tits grow. And drinking your milk made me grow. That’s pretty damning evidence that you’ve got both aspects of what make my condition.”

“M-maybe this is just the blockage breaking!” Starlight responded, though it was obvious she was just trying to reassure herself and didn’t believe a word she’d just said. And even if she did that wouldn’t make her correct. If the blockage was gone, after all, why was Derpy’s body still making earthquake noises?

“Yeah keep tellin’ yourself that.” Derpy turned her attention back to enjoying her new addition. It was, unsurprisingly, very big. About the size of her forearm and noticeably thicker around. Dark grey, with fat, full balls the size of her fist. A very solid starting point, though she was pretty sure that – much like the rest of her – it was going to get much bigger before all this was over. “I, meanwhile, am going to keep workin’ on getting you out of the mess you’ve gotten yourself into.”

“I still don’t see how this-”

“Hic!”

Fwoomph.

“Stop that!”

“Even if I could, I wouldn’t.”

“What is your plan?!”

“I’m gonna get bigger than you and then I’m gonna physically pick you up. Duh.”

“Oh.”

“Yeah I’m surprised it took you this long to figure out.”

“It took me this long to figure out because that’s got nothing to do with solving the problem holy shit!”

“Hey, you only asked for help getting up. You didn’t specify it had to involve shrinking you down.”

“I-”

“Why don’t you just use the same spell you used to shrink me on yourself?”

“The spell doesn’t work that way! Unlike some ponies,I can’t just ignore the laws of physics. It doesn’t delete all that mass from existence, I need somewhere to store it.”

“Oh well I guess you shouldn’t have broken your weird stick.”

“Gee, ya’ think?!”

“Couldn’t you just use like a rock on the ground or does it have to be a weird stick.”

“It has to be a weird stick,” Starlight replied sullenly. “It’s gotta be organic matter, can’t be a rock.”

“Okay well I’m pretty sure there’s gotta be a stick here somewhere.”

“The Staff of Sameness wasn’t just any stick, it was-”

“A weird stick.”

“It was a big stick,” Starlight shot back. “It looked vaguely like it was some kind of magic artefact already, which certainly helped, but the big thing was that it was robust and big. If you tried to store this much size in a twig you found on the ground it would break it.”

“Okay yeah that actually makes sense.”

“And in case you didn’t notice, we’re well above the treeline so I doubt we’d find even that.”

“You’ve made your point,” Derpy replied. “I guess that means our only option is for me to get big enough to move you. Darn.”

“You could absolutely have just walked down the path a bit, we’re not that far above the treeline.”

“Should’a suggested that sooner, babe.”

“I-”

“Hic!”

Fwoomph.

“Just gimme a few more fwoomphs and we’ll be good to go.” At this point, Derpy could no longer play with her dick one-handed. It was just too big for that to be an option. The past few fwoomphs had brought it up from forearm sized to just outright arm sized. Maybe bigger? At this point it reached above her head, easily. Her balls had also gone from fist-sized to head-sized. Fat and full and getting fatter and fuller as her body geared up for climax. Her cock throbbed and pulsed and let loose copious spurts of precum, more and more. It had gotten so thick around that there was no way she could even consider jerking it off one-handed at this point. Even both hands weren’t enough. But that was okay because she was pretty sure she wasn’t going to need to use her hands for much longer. Oh, yes, and speaking of fat and full, of course her boobs were absolutely gushing, torrents of milk flowing down the hill which would almost certainly make the townsfolk’s day very interesting. It almost didn’t bear mentioning, Derpy was so used to it. The dick was much more novel, and so that’s where her focus was.

“I-” Starlight tried again to interject with her own indignant opinion but was interrupted by another hiccup and then another fwoomph. “Stop that!”

“It’s way too late to stop this,” Derpy replied with a big ol’ grin and another fwoomph. They were coming faster now, no longer even prefaced by a hiccup. Just sudden lurches of size. At this point, everything had generally settled, proportionally speaking, and so every fwoomph was just Derpy getting bigger all over. And bigger. And bigger.

“You know I’m pretty sure you’re big enough to help me up by now,” Starlight grumbled, blushing furiously.

“Hm.” Derpy tapped her chin theatrically, slowly standing up and circling around Starlight. “I think you’re right about that. Buuuut...”

“But what?”

“I could help you up, orrrrrr I could take the more fun course of action~”

“What the fuck is that supposed to meahhhhhhhhhhhn!!!”

“Yeah sorry this was gonna happen eventually so we might as well just get it over with now. Fuck, you’re tight~” Derpy said, smacking Starlight’s ass for emphasis as she thrust eagerly. “I mean, of course you are. There’s no way someone like you’s had sex before.”

“F-fuck youuuuuuu~”

“Wait your turn, babe.”

“Fu-fuck- ahn~” Starlight was, thankfully, not really in the state of mind for any more complaints beyond some vaguely annoyed gurgles – and even those were starting to get more and more into it. Which was unsurprising. Starlight was definitely one of those people who really needed to get laid but also point-blank refused to even consider the possibility that they might need to get laid. Derpy had encountered more than her fair share of that kind of person in her past and knew all the signs. “F-fuck... Fuck y- mnnnn~ Fuck meeeeee~”

“Now that’s more like it~” Far be it from Derpy to deny the unicorn what she wanted – and anyway she could feel herself getting closer and closer to climax with every thrust. Better to get as much fun out of this as she could while it lasted, especially now that her partner was finally starting to fucking enjoy herself. Derpy leaned forward, pressing her boobs against Starlight’s back and nibbling the now once again smaller pony’s ear.

Unfortunately, that turned out to have been a bad move in terms of dragging things out. Derpy had already been on the edge, so that extra stimulation to her breasts was enough to set her off. She couldn’t really bring herself to be upset about it, though. Mostly because it was suddenly very hard to think at all. Which was one of the particular realities of this very specific kind of orgasm. It wasn’t just that she had a dick. It was the sheer magnitude of the dick, and of her balls and her boobs and her partner, all in combination. It wasn’t just any one element, and in fact she’d had climaxes just as intense as this one without having grown a dick on many occasions.

But oh man did the dick help. Derpy didn’t have much experience with having a penis, but she had enough experience with having a penis to know the semantic differences between the two types of orgasm. The female version was kind of like riding a train up an increasingly steep slope, a slow but steady climb that built faster and faster as you went on and never really went back down unless you stopped. But for guys it was more like a roller coaster – fast, intense, lower lows but higher highs. Both had their appeals, though obviously Derpy was more used to the former and so the latter had a lot of novelty to her in spite of her experience.

Meanwhile, for someone like Starlight who had no experience at all with the male climax, it was completely overwhelming. Derpy didn’t need to hear that from Starlight’s mouth to know it was the case – she doubted Starlight was capable of words right now, anyway. Just happy sex noises. It probably didn’t help that she likely had minimal experience with the female climax, too, given Derpy’s earlier estimations. In retrospect it probably wasn’t the best idea to just throw her into the deep end.

But on the other hand, fuck it, she’d kind of brought this on herself. The kid obviously had some serious issues, what with the obsession with equality and all. And there was also the fact that she’d apparently enslaved an entire town by stealing their cutie marks and individuality to consider? Derpy could imagine a million ways that this could have played out and most of them went significantly worse for Starlight than getting big and having sex and then probably getting bigger, let’s be real Derpy had enough basic pattern recognition to know that Starlight was absolutely going to want more when this was done.

“Mooooooore~”

“Mnh, called it.”

Starlight completely failed to register Derpy’s commentary, which honestly Derpy didn’t really object to. She was more interested in what inevitable magic shenanigans Starlight was gonna get up to. She’d mentioned that she couldn’t just make size come from nothing, and obviously actually moving was still out of the picture for now. So her money was on-

Starlight’s horn interrupted Derpy’s inner monologue with a bright indigo flash, accompanied by a snap of her fingers and followed by a loud gurgling noise that confirmed the pegasus’s suspicions.

Starlight had, naturally, over the course of Derpy’s still-ongoing orgasm, gotten enrounded quite thoroughly. Not as much as she could have and probably should have, mostly due to her sheer size. But she was still round enough that it had lifted her body higher – and was slowly getting rounder. Or, rather, she had been. But, after casting that spell, her enroundening sloooooowly petered out, and then began to reverse as she converted all that cum into size.

The process was slow, almost imperceptible at first. That was, in Derpy’s experience, generally the case. Either it all happens at once or it slowly escalates. It looked like Starlight was going with the latter, which Derpy was totally down with. This was a pretty fun dynamic – Starlight turned Derpy’s cum into size until she got too big for Derpy to fuck at which point Derpy could just drink more of Starlight’s milk and get bigger until she was too big to breastfeed from Starlight. Lather, rinse, repeat until bored.

... Which, actually, now that Derpy thought of it, was potentially a problem. After all, while Derpy was used to these shenanigans, Starlight was still a newbie. And, well, Derpy could attest to the fact that it was kinda hard to keep your head cool as an expert. For someone like Starlight who Derpy was pretty sure hadn’t ever had sex before at all, let alone this specific kind of sex? It was very likely she was going to go a bit grow-crazy. Hell, it was almost a certainty.

“M-more~” Starlight moaned, as if to reinforce Derpy’s worries. Though, admittedly, they weren’t exactly the most pressing concerns. Like oh no Starlight was going to do something unexpected and get bigger. The worst case scenario was that Derpy might end up getting buried beneath her ass or balls or something which would just be a tragedy. “Biggerrrrrrrrr~” Starlight’s growth sped up with perfect dramatic timing. She was, Derpy noticed, not directly scaling her body larger. Her boobs and butt and balls were all growing slightly slower than the rest of her. That made sense, though on the other hand Derpy wasn’t entirely sure how intentional it was. It could be Starlight trying to reclaim some amount of mobility or it could just be a happy accident of how the spell worked.

The point was that Starlight wasn’t just getting bigger, she was reclaiming her mobility. Which was a problem, Derpy realized, because that lack of mobility was the only reason Starlight hadn’t been able to turn the tables. Yes, her breasts were too big for her to stand up, but her muscles were decidedly buffer than Derpy’s. And, more pointedly, after transferring all of Derpy’s orgasm into size, Starlight was bigger than her.

And, it seemed, hadn’t quite forgiven her yet.

Starlight moved surprisingly fast, given her raw size. Within seconds she’d gone from doggy-style to cowgirl style, pinning Derpy to the ground with her raw bulk, cock in between Derpy’s tits. “Looks like it’s my turn now.”

“Yep, looks like it!”

“I- god dammit could you at least pretend to be distressed?!”

“Nah, I’m havin’ a blast.”

“Well, fine, if you’re gonna be that way then I’ll just do this!” Starlight punctuated her presumed threat by reaching down and grabbing Derpy by the tits, which had predictably milky results.

“Well I mean if you wanted to squeeze my tits you coulda just asked?”

Starlight dug her hands in deep, pressing them against her shaft and thrusting eagerly.“I’m not playing with your tits!”

“Sure looks like you’re playing with my tits, babe.”

“Yeah let’s see if you’re still laughing after I actually do the thing I’m gonna do.”

“Maybe you should, you know, do it then?”

“Hmph!” Starlight’s horn lit up, and the glow slowly spread down to her hands. “You see, I said I couldn’t drain my size into something else, but that was technically not true. All I need for the spell is something sufficiently robust and made out of organic matter to store the excess size in. Like the Staff of Sameness.” A smug smirk spread across the unicorn’s face as a familiar sensation blossomed in Derpy’s chest. “Or myself.”

The sensation of shrinking down was, at this point, annoyingly familiar. Derpy had shrunk down so many times today that frankly she was getting sick of it. The novelty had well and truly worn the fuck off at this point. Thankfully, she was at least fairly sure that Starlight was no longer interested in keeping Derpy shrunk. Hell, she was shrinking slowly enough that were it not for that fucking growth block she’d probably be able to outpace it.

Which, like, speaking of which, god she was fucking tired of the growth block. It had turned out to be significantly more durable than she’d expected it to be. Which was like 90% of why Starlight was able to get the upper hand. Derpy didn’t even mind Starlight having the upper hand, at least a little. Things being too one-sided was boring. But this was too far in the other direction god dammit. She honestly had to give the unicorn some amount of credit – she’d done a better job at managing Derpy’s size than anyone else had. It had lasted for, like, more than a few seconds! That was significantly more than her own efforts had lasted, though she was still confident that it would eventually break.

Starlight seemed less confident in that regard. “Yessssss!” she hissed eagerly as she grew. Just as Derpy was shrinking fairly slowly, so too did Starlight grow slowly – though, considering that Derpy was in fact shrinking, it felt a lot more than it probably was. Her perspective was skewed. “Biggerrrrrrr~” Of course, that wasn’t to undersell Starlight’s growth. Because, skewed perspective or not, Starlight’s ass and balls were covering more and more of Derpy’s body at a mildly alarming rate. It wasn’t the first time Derpy had been mostly smothered by balls, but she generally preferred that to happen on her terms.

Of course, on the other hoof, there was something to be said for letting the universe take the wheel. Sometimes it was fun to get caught off guard. And, well, sometimes reality had better dramatic timing than she did. The rumblings her body was making had, by this point, devolved into background noises that she’d mostly tuned out so she could focus on what was actually happening. Or at least that was her excuse for why it took her so long to notice that it was getting louder. And louder and louder. And beyond that, there was a very familiar feeling. One that Derpy knew the significance of immediately, though it was much more intense than she was used to.

“I’m going to drain you dry. And then, when you’re as small as you can get, I’m going to make you grow so I can drain you all over again, over and over and-” Starlight’s size-drunk ramblings slowly petered out. Derpy couldn’t see it, obviously, but she didn’t need to in order to know the exact expression of mild confusion slowly spreading across the unicorn’s face. “... What the fuck is that noise?”

Fwoomph.

“There we go. Took long enough.” Derpy took a brief moment to stretch – she hadn’t exactly spent a long time pinned beneath Starlight’s balls, but it was still nice to be able to move again. “That noise, by the way, was your dumb growth-block finally breaking.”

In the course of Starlight’s growth, Derpy’s dick had slipped out of her. And so the unicorn was thankfully spared from being impaled on a dick bigger than she was. Instead, she found herself pinned between cock and tum, firmly wedged in place until Derpy reached in and plucked her out. “You were sayin’?”

“I, um...”

“Hey, hey, no need to get sheepish, babe. That whole you grow and then I grow thing sounds fun! You’re gonna wanna get started on it ASAP though, ‘cause it’s my turn to do the penetrating.”

Starlight swallowed heavily, sparing a pointed glance at Derpy’s dick.

“Now,” the pegasus said, licking her lips eagerly. “Let’s get this party really started.”

~~~~~~

“So of course then she cast the size draining spell on me again, she kinda didn’t have a choice? I mean obviously I wasn’t gonna go forward with things if she didn’t do that, or like at least cast a stretchiness spell on herself or something? But she didn’t need to know that, more fun that way. Anyway, she cast the spell, but at that point I was so backed up that it really only slowed me down and gave her time to catch up a bit. Then I just sort of let her do her thing until she was big enough I was pretty sure she wouldn’t break mostly and-”

“Okay I think that’s enough details, Derpy.”

“Aw, but I was just gettin’ to the good bit!”

“I can guess what happened next,” Twilight replied tersely. “Let’s just skip to the end.”

“Okay well there was a lot of milk between the two of us and apparently by this point some had gotten into the water supply so-”

“Little farther forward, Derpy.”

“Oh.”

“Anyway, this is her?”

“Yes,” Starlight said sheepishly. “I gave everyone their cutie marks and their size back, but... obviously I’m not exactly welcome to stay on as mayor.”

“Well, you’re more than welcome to stay in Ponyville, so long as you behave yourself,” Twilight said, visibly relaxing a little now that talk had moved on from the sex and growth and such. “We’ll be keeping an eye on you for now, though.”

“Oh, that’s understandable,” Starlight replied with an awkward wave. “Honestly I was expecting you to be more harsh.”

“Well, I believe that no one can improve if you don’t give them the chance.” Twilight’s eyes narrowed. “That being said, though, are you sure you gave back all the size you took.”

“Oh. Yes, about that.” Starlight shuffled awkwardly, clearly not used to being quite so big as she was. “It, ah, turns out that there were some long-term side effects to my... encounter with Derpy that I didn’t predict.”

“Yes. Derpy has that effect on people,” Twilight replied tersely. Neither mare held a candle to Derpy, of course, but that was like saying a lake was smaller than the ocean.

“You know,” Derpy interjected, “I seem to remember you being a lot more enthusiastic about replicating my condition.”

“That was before I discovered that it stacked multiplicatively with getting alicorned.” Twilight sullenly crossed her arms beneath the bikini-clad behemoths on her chest. They weren’t at Derpy’s level, of course, but they were still easily more than twice the size of her head. Starlight was pointedly trying not to look at them, but that was difficult considering they were almost perfectly at eye level.

“... I should probably invest in some swimwear.”

“I’d also suggest learning some warmth spells. Trust me, winter is a bitch when you can only wear bikinis.”

“Right. I’ve just been casting waterproofing spells on my normal clothing, but it’s... not exactly comfortable.” Starlight shuffled awkwardly some more. “And my clothes don’t fit anymore anyway, so- Ack!”

“Honestly,” Derpy interjected, squeezing Starlight’s head-sized breasts from behind. “The bikini thing is a perk not a downside.”

“Not in the winter it ain’t.”

“As far as I’m concerned, any reminder of how stupidly massive I am is a plus.”

“Ah. It’s, um. It’s fine. I’ve kind of learned to enjoy my differences, as it were.”

“Oh! Yes, that’s right, speaking of which.” Twilight’s demeanour brightened, and with a snap of her fingers a scroll and quill materialized in her hands. “Friendship lesson time!”

“... What lesson?”

“It’s a thing,” Twilight said. “Essentially, whenever an incident happens, it’s sort of tradition to write a little letter to Princess Celestia about what we learned from it.”

“Oh. Okay?” Starlight shrugged. “I’m not one to go against tradition.” She put a finger on her chin in thought for a few moments – and, in the process, framed her impressive cleavage unintentionally. She’d clearly not gotten used to manoeuvring her way around her ample chest just yet.

“Anything coming to mind?”

“Hm. How about... ‘Never antagonize Derpy’s boobs unless you know what you’re getting into’?”

“that is not a friendship lesson”

“I think it’s a great friendship lesson,” Derpy interjected.

“Hmph. Well, if you think you know better than me then you can write the letter,” Twilight retorted, using unicorn magic to float the quill and scroll over to Derpy. “I am going to go have a fucking nap. It’s way too early for this.” She turned around, waving vaguely at the two. “Oh, and if you decide to use the kitchen, don’t use all the creamer. I’m gonna want a cup of coffee when I wake up.”

“Hmph,” Derpy replied as Twilight left, crossing her arms in annoyance.

“She seems nice.”

“She’s a bit of an acquired taste.”

“I can imagine.”

Derpy shrugged. “Anyway, c’mon, I’m gonna go replace her creamer with my creamer.”

“Um... Should you really do that? It sounds like a recipe for disaster.”

“Yes that’s why I definitely should do it,” Derpy said as she headed off towards the kitchen. “You gotta learn to appreciate the little things in life.”

“Like pranking royalty with growth milk?”

“Yes.”

Starlight stared at Derpy as she headed towards the kitchen, although she had a hard time figuring out where to stare. Though, on the other hoof, Derpy didn’t exactly seem to mind being stared at. And anyway, she was easy on the eyes.

After a moment of thought, Starlight followed the larger pegasus. She was, she decided, going to like Ponyville. She was going to like it a lot.