Daytrip to Canterlot

Visiting Canterlot and going on a palace tour had been Berry's idea. Derpy had been surprised, since she hadn't imagined that her lover would much enjoy the place. The earth pony didn't particularly care about other ponies, particularly not ones that put on airs. She'd be happy to spend the weekend at home with their daughters rather than square the younger two away with sleepovers. Amethyst Star, at least, might enjoy the novelty of having the house all to herself.

Of course, they'd been in a relationship for long enough that it hadn't taken Derpy much to realize that she'd probably be providing all the entertainment Berry would need. The earth pony enjoyed seeing Derpy all hot and bothered, and having her huge, milky tits paraded in front of strangers who hadn't had a chance to get used to them would make it very difficult to keep her composure indeed.

Derpy loved being seen. Her tits were amazing, they needed to be shared, and she was glad every day that they were now large enough that even when she technically kept them covered, they were impossible to hide. Fortunately, her job as a mailmare kept her moving around in public every day for people to appreciate. Better still, every landing was practically a lewd act, sending her great rack bouncing and wobbling.

She'd milked herself intensively during her morning shower. It wouldn't keep the arousal at bay, but it'd probably at least get her through the train ride without some milk-related accident.

Derpy had taken a window seat, Berry sitting next to her. She'd been a little disappointed to be able to board the train without her breasts touching either side of the door, and her tits only filled her lap if she slumped forward, adopting a rather poor posture, but that would change in the near future. While her rack was wider than the rest of her and already brushed against the wall, she could easily imagine larger breasts invading her partner's personal space. Berry would probably fondle her sneakily if her arm was hidden behind a massive boob.

Just thinking about Berry's hands on her breasts caused Derpy's nipples to grow erect. They were the size of shot glasses, kind of big even on her huge breasts and impossible for her cheap t-shirt to hide. Two major parts of Derpy did not like feeling in any way contained or restrained at all. She went topless at home and while she hadn't made a study of it, she felt that she required fewer masturbation breaks compared to her work hours in full mailmare uniform. Part of that was likely the lack of an audience to rile her up, but she also imagined herself bursting out of her top in a tide of milk and titflesh much less frequently when she wasn't wearing one.

Derpy tried to avoid such thoughts. It would be easier if they had any of their daughters along, her great boobs were always at their most cooperative when she was paying attention to their children, because being a good parent was more important than her personal indulgences. Naturally, Berry had planned the trip just for the two of them because they'd both enjoy Derpy's efforts to control herself, as well as her eventual failure.

She closed her eyes, trying not to notice how other passengers looked at her chest. Every so often a shiver of delight radiated from within her breasts, as though they independently felt the gaze of onlookers brush across them. "What do you think Sparkler is gonna do alone at home?" Derpy tried to distract herself.

"Hm." Berry huffed, apparently amused. "Sit in my recliner while she reads? We got a boring daughter."

"Well behaved," Derpy corrected her with a smile. Their oldest daughter had been a headache just after the adoption, presumably to test if they'd send her back into the foster system when she became inconvenient, but since then, Sparkler hadn't made waves and she obviously enjoyed being a big sister. "Glad you connect so well."

Berry, like Sparkler, hadn't had a great childhood and it had been something for the both of them to connect over. Both also seemed perpetually touch-starved, and though they hid that in public, they enjoyed cuddling with Derpy and the younger daughters. That trust and tenderness always filled her with immense happiness and satisfaction, more than enough to sooth the usual demands of her body for the duration and some time afterwards.

"Mm." Berry made a noise of agreement. "She's worried we expect her to move out as soon as she's done with school. Hasn't gotten to enjoy our home for as long as the younger girls will have."

Derpy had been a restless youth, wanting to see the world outside of Cloudsdale, and leaving her home town had been a huge relief to Berry, so they weren't well positioned to understand how their daughter felt. Still, if Amethyst Star felt she wanted a few more years of a stable, loving home life to make up for her first decade or so of her life, Derpy wouldn't complain. "You told her that we won't?"

"Yeah."

They passed the time with more idle conversation about their kids, which always was a reliable way to spend time without becoming hornier than she already was.

Of course, Berry just had to betray her. She would hardly have proposed the trip for just the two of them if she wasn't going to try and torment Derpy innocuously.

"By the way," the earth pony started idly, "I brought a couple changes of clothes, just in case of an eruption."

Derpy sucked in air as she flushed with further arousal. To the ears of other nearby passengers, it had probably sounded like a reasonably pragmatic statement. Some ponies blushed, obviously assuming now that her exceptional breasts lactated. Her fat nipples, still erect, throbbed so insistently it had to be visible to anyone looking at that moment. Derpy hoped that it created the impression that her nubs were reaching for hungry mouths.

Bringing extra shirts was, of course, thoughtful of Berry. But the important part was that contemplating the inconveniences of Derpy's tits and planning around them was incredibly hot. Of course her great glands were so monstrously fruitful that staining her shirt was inevitable. Derpy had become almost incapable of embarrassment or shame when it came to her body. She dreamt of the day her rack would be large enough to leave her stuck in a door somewhere public.

A bit of particularly uneven track sent a jolt through the train, making her boobs jiggle. Celestia, they were so soft. Derpy didn't understand how they could be so beautifully soft to play with while retaining their proud shape unaided. Perhaps whatever magic made them so excessively bountiful also ensured that they were pleasant in every particular for her and Berry?

They sloshed audibly, something Derpy would never get tired of. As far as her understanding of anatomy went, boobs didn't have some interior space for milk to splash noisily around in, so the sounds were clearly a delightful way for her body to communicate and draw additional attention.

Derpy willed her breath to remain steady, adjusted her position slightly, then closed her eyes again and allowed herself to enjoy the increased warmth between her legs and the slow waves of pleasure washing over her thoughts. She'd learned to enjoy the ride, to enjoy the way she always wanted to touch herself and be touched, wanted Berry to play with her amazing tits. Derpy couldn't recall how it felt to not be horny. Over the years she'd become accustomed to it. It was her new normal. Besides, she had unlimited milk on tap, so being always down to fuck didn't even compare in terms of weirdness.

Maybe another pony who hadn't been changed by her magical rack might feel perpetually unsatisfied? As far as Derpy was concerned, there just was never too much of a good thing, especially not when it came to Berry making love to her.

It was inevitable that her lust would continue to escalate today. Her thoughts would grow fuzzy and sluggish, although slowly. Derpy had, after all, a lot of experience with her unrelenting libido. Even under normal conditions she'd inevitably encounter sights or thoughts which would excite her further, without Berry going out of her way to tease her.

The earth pony leaned against Derpy. Being the taller mare made it easy for Berry to talk quietly near Derpy's ear. "Lots of people are gonna be telling their friends about seeing you. Don't know how many are gonna believe them, yeah?"

Derpy hummed, smiling lazily. Her amazing breasts were no real burden to her and she always dreamed of being larger, so it was nice to be reminded that her rack was already staggeringly large and impossibly well-shaped by the standards of any other pony. They'd probably each be over a foot across at their widest point if their great heft didn't form a beautiful natural cleavage. They retained an attractive, pert shape, jutting proudly rather than hanging heavily, which she couldn't explain in any way other than magic, and which was the only reason they weren't resting in her lap quite yet – she was nearly there. There was just enough sag to make them seem natural as long as observers didn't think too hard about it, and they needed no real support. Despite their improbable ability to retain their shape, they were enticingly soft to the touch whenever they weren't engorged with milk.

"Still," Berry added, "I guess they're not going to talk about having seen the milkiest jugs ever." Somehow she made that sound like a regrettable missed opportunity.

"I don't want to pay for clean-up, Berry," Derpy huffed, pleasure pulsing from her breasts. They were clearly eager to demonstrate to all and sundry what they were capable of. They felt so alive, especially in moments like this. She became more acutely aware of her output. Derpy's great glands hadn't ceased production since her pregnancy, when their size had still been wholly unremarkable. She knew with absolute certainty that she could never give as much milk in any span of time as she produced, that every time she allowed herself to gush uncontrollably, she'd end with the amazing feeling of being fuller than before.

When her mood was right, she thought she could feel every drop of milk she hadn't shared in the preceding years, oceans of it with no use or existence beyond the exhilarating knowledge of being the most bountiful creature alive.

Derpy knew that Berry favored a supernatural explanation. Her boobs were already clearly magic, so it would be pretty boring to assume that Derpy had just latched onto some delusion to make her ability to produce impossible amounts of milk on command more complex than it was.

Were Derpy's boobs bigger on the inside? That was fun to contemplate whenever Berry sank her fingers deep into her yielding flesh. Or perhaps there was some kind of milk dimension of infinite capacity she'd been connected to in some cosmic accident.

Clearly, her magic boobs were a force for good. Derpy never felt compelled to feed anyone more milk than they were interested in, and although she needed sexual and lactic release regularly and frequently, these requirements had never gotten in the way of her family's emotional needs. Despite this, sometimes it pleased Derpy to imagine that her heroic tits were holding back some callously indifferent force of endless vitality, her plump nipples keeping the world safe from an apocalyptic deluge.

Still, her boobs were wilful. She'd never want to force her milk on anyone, but her exhibitionist side dearly wanted everyone to know that the option was available. She felt an intense, pleasurable churning in her breasts, and she imagined the sea of her milk reserves being unsettled by the storm of her lust. Derpy had to bite back a moan, drawing on her years of experience being a functional adult despite feeling tremendously horny.

Berry, of course, loved how easily her words could rile up Derpy and her breasts. "Knew why I brought extra shirts," the earth pony commented as the first fat dollops of milk escaped Derpy's control and began soaking her shirt. She wished there was a mirror nearby, as the sight of a thin shirt clinging wetly to her large nipples was tremendously enticing and best viewed frontally.

Derpy clucked her tongue in faked disapproval. "I'm gonna be horny as hell by the time we arrive," she informed Berry, keeping her voice pitched so only the nearest ponies would hear and assume she had spoken too loudly unintentionally. "You know it'll be a mess if I bring myself off while backed up, too." She rubbed her thighs together. Imagining herself spraying milk in front of a crowd of perfect strangers only made her arousal worse. She'd decided on a skirt of modest and sensible length today, and she was pretty sure hardly anyone would notice if Berry would just sneak a hand under her tits and past the skirt's waistband. She'd need bigger tits to make absolutely sure it could be done without anyone noticing.

Instead, Berry just took Derpy's hand into her own. Much tamer than what Derpy had been thinking about, but she wasn't going to say it was worse. The earth pony also gave her a brief, questioning look. Derpy knew that the other mare would stop trying to work her up if she asked. Of course, her boobs were already stirred up, aching for release, and Derpy badly wanted to feel Berry's hands on her tits, maybe her teeth gently nibbling on her stiff nipples.

That wouldn't just go away even if they spent the rest of the train ride chastely holding hands. Derpy would need release either way. Besides, their lives weren't without stress, so having some real fun when it was just the two of them was really just proper self-maintenance. It'd also be a terrible waste to hide in a bathroom somewhere to milk herself to a quick climax when there were all these strangers to amaze and astound with the fantastic excesses of her body.

She shivered with raw need, biting her lip and giving Berry an encouraging nod to signal that she was ready to make a splash.

"Y'know," Berry muttered in response. "I've always appreciated how responsive your jugs are."

Derpy liked that as well. It was beautiful to hear fantasies of her own continued growth voiced by another. "Well, you're supposed to enjoy them."

"I do," her lover agreed. "Kinda wonder if it goes beyond making you randy. Y'mind if I try makin' a request?"

"You know I trust you." In fact, Derpy was quite happy to play along. The big earth pony was pretty trivial to satisfy sexually, but could get creative with the ways she drove Derpy wild just by talking about her boobs and how big they might get. She couldn't imagine what Berry might ask of her, but surely her boobs would play along to please the other mare.

Berry shrugged. "I was just thinkin' it'd be fun if you got stuck in the doors while getting off the train. If your rack was that wide, I could stand behind you and really sink my hands into them as I push, while you'd make ponies scramble not to get hosed down with milk on the platform, yeah?"

"Mhm. Lovely idea," Derpy agreed, breathily. The idea of being so big that it got inconvenient for the people around her was really doing it for her. Her great breasts throbbed in anticipation, as she'd had that very thought when she entered the train.

"Well, I don't feel like waiting," Berry stated with a grin. "I want that today. Not askin' for anything permanent, but you can't tell me these jugs aren't magical enough for a bit of fun." The taller mare lowered her voice further. "C'mon, Derps. Grow for me."

Derpy bit her lip as she felt her body react to Berry's words. Her fat nipples twitched and her boobs seemed to jiggle with internal tremors, set to some languid rhythm, like the beating of two great hearts. Each one was accompanied by a shockwave of pleasure crashing through her. It was becoming increasingly difficult to pay attention to anything but her tits and the feel of Berry's hands on her own.

She felt overwhelmed by impressions of rushing liquid and knew her glands frantically increased their output. Although Derpy had somehow managed not to cum on the spot or even moan too loudly, she couldn't stop herself from giggling with sheer glee when she felt the already great weight of her rack increase and the bulk of her left tit shift as it grew and fought for space against the wall.

"It's w-working!" Derpy grinned. Physical pleasure aside, it simply delighted her to know how far her body could go to please Berry. She didn't feel the blissful contentment she'd come to associate with new permanent growth. This, clearly, would purely be for the sake of pleasure.

With her huge, growing tits finally sitting solidly in her lap, Derpy enjoyed the way her knees pressed into their undersides. As her right boob encroached further into Berry's personal space, the bigger mare muttered something warm and approving in Derpy's ear, although her raw need was making verbal communication difficult. She was more aware of every inch of titflesh and the endless milk roiling and churning within than of her surroundings.

Another pony would long since have climaxed, and it wasn't actually difficult to get herself off in a hurry during a lunch break or something, but as much as Derpy's breasts were unique and still growing, so were the dizzying, helpless heights of arousal she could achieve with the proper patient ministrations and enough time.

Derpy tried to hold still, trying not to accidentally tip herself over the edge and start cumming before their arrival, but her tits were growing so damnably sensitive, she felt every shift of her flimsy shirt across her skin as the top started straining against her mass. Despite their increasing weight they remained firm, fat and round. Seated as she was, their upper slopes rose to take up more of her lower field of view.

She felt one of Berry's hands on the underside of her right breast, which already half sat in the earth pony's lap anyway. Derpy wondered what it said about her that she could hardly pay attention to the world around her as she struggled not to start groping herself, but could feel everything happening to her tits with exacting clarity as Berry traced letters on her skin.

Derpy was pretty sure she felt Berry spell out 'Love you' and the secret nature of that display of affection made her giggle again before she pressed a kiss to Berry's cheek. Of course, she recalled pretty clearly that her lover had originally joked she'd have to communicate that way once Derpy grew vast enough that most of her rack was too far from her ears for talking or shouting. Her breasts always throbbed in warm approval at such fantasies.

The rest of the ride was a blur to Derpy. At least once a concerned sounding pony talked to them, and Berry replied smugly before the other pony left, flustered. Maybe Berry had exclaimed that Derpy was just monstrously horny. Mostly Derpy just stewed in the feeling of raw potential, straining to be released. Berry's proximity and the earth's pony's steady breathing allowed Derpy to maintain control. The other mare wasn't audacious enough to nap after priming her to make a mess, but having the big mare relax against her body was fulfilling to Derpy even while she felt such desperate need.

When the train finally stopped, Berry had to help pull Derpy up from her seat after grabbing her backpack, although she managed to stand on her own afterwards. They were both well-suited to handling Derpy's boobs, Berry was strong because she was an earth pony, and Derpy was strong because she was built to have immense tits.

Less well suited to handling Derpy's boobs was the interior of the train car. Although her shirt yet lived, it had survived only by riding up until it covered nothing below her nipples, and there was no denying that her rack was much wider than it had been at the start of the journey, extending further ahead of her and hanging lower than before. She'd been looking forward to being truly too large to easily navigate normal pony places for years, and the realization of the fantasy instantly shattered her self-control.

Electrifying pleasure sent a tremor through her body as Derpy felt herself bump into and drag past the back of another seat. She came with a quiet moan, swaying on her feet momentarily. The release returned a modicum of clarity to her, but her tits were much too fired up now for a single climax to suffice. If she hadn't been so intent on making a scene the way Berry had described it, she'd already be gushing milk. As it stood, she felt herself growing engorged. If her nipples weren't so large and erect, her shirt would have long given up its hold on her rack.

Berry, walking behind her to help steady her, called out. "Best clear space on the platform! She's backed up enough to make a major splash!"

Derpy's bloated breasts sloshed noisily again, throbbing impatiently. The smell of her thick cream filled the space around her as the wetness around her nipples spread and milk ran down her exposed lower slopes. It had been a long time since Berry and herself had deliberately incited her urge to spread her milk around to such a degree. Much like her lust, it was a need which was most easily sated early and often in her day to day life.

Obviously, Derpy could have easily exited the train one big boob at a time. It would likely still have impressed anyone watching to see a pair of tits big enough to make it necessary, but it would have been the more boring option. Cramming herself into the open doorway was much more satisfying. She could probably have pushed herself through under her own power, but it was rare enough that Berry wanted to participate in one of Derpy's public spectacles.

She felt the exit's frame digging into her titflesh harshly, although her top suffered more from it, finally losing its hold and letting her impressive nipples go. If Derpy hadn't just wedged herself in place, her breasts would probably have dropped a bit and wobbled delightfully.

Derpy could see the passengers who'd disembarked before her push their way through the small number of ponies who'd planned to get on the train here. Those, particularly, were anywhere from puzzled to awed by the brazen display of her huge, immodest milk tanks. The first squirts of her milk arced to the ground.

"Make room, she's not gonna hold it in much longer!" Berry's second warning made Derpy grin smugly. She looked forward to crushing whatever mental images her audience was putting together, trying to predict what came next.

Feeling the eyes of strangers on her naked chest, being impractically large, feeling full to bursting with milk, Derpy had expected it all. What caught her by surprise were the tight feelings at the cores of her breasts, the sudden urge to just grow and grow until she exploded out of her restraints. She'd never liked to wear much, but she hadn't expected her tits to react this way to more sturdy containment and couldn't wait to experiment more. Derpy came again. She moaned shamelessly as her control slipped and two long streams of milk splattered thickly onto the platform, mere hints of her abundance.

Much as she loved the situation, she planned to attempt something similar in private, because Berry drew the line at actually fucking her in public and Derpy herself wasn't feeling quite brazen enough to drop the thin excuse of her out of control breasts forcing her into making a spectacle. While Derpy's boobs and nipples could produce such spectacular orgasms that she didn't even need to touch her own sex, the idea of being completely naked while stuck like this as Berry pleasured her was exciting.

Derpy felt powerful as her breasts grew, forced larger by the relentless pressure of her milk. She felt as though she really could outgrow her predicament, even though it wasn't wholly real. "S-so much," she gasped. "Help me, Berry." She felt every detail of the material her breasts strained against, but there was no pain, and whatever slight discomfort she felt paled against the extraordinary sensations from within, more and more milk fighting for release.

She felt and saw Berry reach past her upper body on either side and place her strong hands on her tits, palms near the back, fingers digging into their sides. Derpy gasped joyfully. She'd recognize her partner's rough, calloused hands, that faded scar on her palm, even if she were being groped by a dozen people at once. Her bloated tits resisted at first, but Derpy practically felt the pleasure of Berry's touch radiate outwards through her body, when the feeling reached her nipples they trembled, twitched, and unleashed new torrents of milk, reaching further than her previous release.

Berry's hands and fingers sank into Derpy's newly yielding titflesh as the internal pressure decreased, and the earth pony's happy sigh by her ear brought Derpy over the edge to another climax, overcome with giddiness at another reminder that Berry enjoyed her amazing body as well. "Haah. They're a-all yours, Berry." The taller mare was playing along because it amused her to mess with people, but what she loved was getting a good grip on Derpy's boobs when they were soft and inviting. That Derpy loved having them handled roughly just made the two of them particularly compatible in that way.

"It's time," Berry warned her before a particularly firm squeeze, pressing in against her breasts and giving Derpy a firm shove from behind with most of her weight.

Derpy felt herself drag harshly past the door's frame as she slipped from Berry's grasp and stumbled forward, still pumping out milk. Her legs were weak from previous climaxes and Derpy fell to her knees in the puddle of her cream, then slumped forward onto her tits. She noticed a few spectators wincing at the rough landing. Derpy would have liked to reassure them, but telling them that the works of ponies could never hope to contain, let alone harm or slow her two unstoppable forces would just make ponies worry for no gain. Instead, she started massaging the flanks of her great breasts, from their bases in the direction of her nipples. Her glands felt even more alive than usual. Derpy made no effort to hold back moans as her tits surged larger and the force of her lactation redoubled, nicely measurable by how far her milk sprayed before splattering onto the platform.

"Alright folks, stay clear, don't blame us if you get wet." Berry herself made sure to stay either behind or at Derpy's sides as she addressed the remaining onlookers. Some had already gone off to board the train through other entrances, but there were always enough ponies who wanted to see the show to its end.

Derpy spent some time simply milking herself with increased force, which appeared to diminish her size again. "Hnng ......... I'm jus-just too small to hold it all," she whimpered. She could hardly go around telling people just how large she would grow in her fantasies, but she could at least imply that her current, plainly impossible, size was in some way insufficient.

Making a show of trying to get up, Derpy staggered a half step forward before dropping her weight onto her chest again, having succeeded in rolling forward until her nipples were trapped against the rough ground by her own weight, engulfed by the rest of her mass pressing against the platform. She keened wordlessly as another climax wracked her from the sheer joy of discovering a new sensation as her milk was forced out from underneath her flesh, bubbling forth in a froth by the sheer force of her lactation.

Berry drew attention to herself by unexpectedly responding to Derpy's words. "And I keep telling you," she made a very good show of sounding exasperated with a repeat argument, "volume going up faster than, uh, diameter is always gonna work against you if most of that volume is, is glands, yeah? You can't outgrow the problem!" Maybe she'd been reminded of that reality by some piece of homework their daughters had been doing. Whatever the case, Derpy could kiss the other mare for playing along and also for reminding her that her monstrous productivity was always going to increase faster than her size would.

"Uhm, should we look for a doctor?" It was a sensible question for the spectator to ask, and Derpy always appreciated ponies with a drive to help.

"Nah," Berry replied, unconcerned. "It's a known issue. Hormones or something. We know how to manage it and usually she gets through her days without ... this." She gestured vaguely towards Derpy.

Derpy was the centerpiece of a sea of milk by now, and she decided to act as though she was trying to do the sensible thing and aim herself at the edge of the platform so her milk wouldn't pool to such an extent before running down to the track bed. She couldn't stop herself from hoping that her display would be seared into the minds of her spectators so thoroughly that they wouldn't be able to keep from thinking of her amazing rack whenever their minds weren't otherwise occupied with their life. Contemplating her effect on other ponies made her cum again, and her mind briefly ground to a halt before she could achieve much other than shuffling vaguely sideways. At least her boobs didn't resist her much, all that milk escaping from underneath her bulk apparently reducing drag.

She couldn't recall the last time she had felt so incredible. She'd made a spectacle of herself in public before, but always in Ponyville and never with as much cooperation from Berry as today. Clearly, making it a shared activity improved the game immensely. Derpy had to take a moment to simply rest against her rack, enjoying its warmth, feeling her glands pulse and throb, clearly eager to continue spilling more milk than even her currently enlarged breasts could conceivably have held. She felt them grow engorged once again, posing a tantalizing question: Could she spray milk with enough force to shift the massive weight of her tits off her nipples? Perhaps once she attained her current size through regular growth, which always included her nipples – they weren't currently larger than they had been at the start of the day, so the upper limit of her output hadn't increased, although she hadn't reached it yet.

"Lemme try something," Berry muttered before stepping around her. "Legs out," she barked a command. Derpy complied, eager to see what the other mare wanted to contribute.

Berry grabbed Derpy by the shins and lifted her up, adjusting her orientation so her head faced the edge of the platform. The train was only just leaving. Derpy briefly felt somewhat ridiculous, being pushed closer to the edge like a wheelbarrow, her tits slick and slippery from milk, but noticing her own bow wave in the mess she'd made forced her to add another screaming orgasm to her tally. She couldn't get enough of the ridiculous excesses of her body, or how her sheer size altered the way she and others had to handle it.

Derpy badly wanted to tell the remaining onlookers that this wasn't some medical emergency she had to endure, she wanted to grow until she crushed the station building, to produce enough milk to flood the track bed from here to the foot of the mountain.

"Well, uh, she seems to be enjoying herself," someone commented.

"Yeah," Berry agreed as she helped Derpy into a sitting position, breasts overflowing her lap so her milk could spray straight off the platform. "Kind of a problem, actually. It feels good, obviously, but, uh, getting hot under the collar risks stirring up her production, which keeps feeling good ..." Berry trailed off for effect. "Yeah, we're in public, but she's got to stay on top of both if she doesn't want to fall into an uncontrolled growth cascade. Then we'd really be here all day," she concluded, making an admirable effort to sound like that was a problem she had experience with.

There was a kernel of truth to the explanation, Derpy supposed, but considering how pleasurable it was for her to milk herself in front of an audience, she easily had both her lactation and her lust covered, two birds with one stone, really. She strained, briefly, to look at the ponies around her without going back to flooding the platform. The look of almost horrified fascination some of them sported stirred Derpy's body into a frenzy. Her immense tits gurgled and groaned, milk churning within, and another growth spurt made them inch closer to the edge. "Hah ..aah! D-don't give them ideas!"

"No!" Berry sounded appropriately panicked as she stepped up behind Derpy. She felt her partner grasp her shoulders and pull her back into a supine position. As Derpy would have predicted, she was immediately trapped under the weight of her own fat knockers. That she could still draw breath easily just reinforced her belief that she was made to have gigantic tits.

Her milk hit the roof above the platform, normally meant to keep rain off waiting travelers, with the force of two fire hoses. Derpy thought she heard some dismayed exclamations, but really, anyone who'd stuck around for the whole theater up to this point only had themselves to blame for getting a bit wet. Berry, grinning down at her, obviously felt the same.

"Guess getting you under control is a two-pony job today," the earth pony commented as she positioned herself by Derpy's head and reached down to grab her nipples. Not only was the feeling of Berry establishing a firm grip and pulling up quite delightful, it also allowed Derpy to reach down and stick her hands past her soaked skirt's waistband and start masturbating enthusiastically, fingers in her wet slit and thumb working her clit.

Berry lowered herself into a squat, apparently experimenting to see what the best stance for the current situation was. Still, she gamely kept milking Derpy, at least making the attempt to aim towards the tracks instead of straight up or to the sides, depending on how Derpy's boobs would come to rest when unattended.

"Hff..." Derpy shuddered. Maintaining coherent thoughts while so overloaded with sensation made her feel accomplished. "Would love to have ... have this as a painting. Over our bed."

"What? You soaked top to bottom in your own milk, bringin' yourself off furiously while I'm struggling to milk these jugs down to their usual size?" Berry sounded amused. "Maybe when all three of the girls are old enough we could risk hanging up something like that."

At last, both Derpy's libido and her breasts were coming back under control. A few concluding climaxes while Berry kept milking her a little longer than necessary to get her back to her regular size, and Derpy felt a bone-deep contentment. The embers of her lust were still and would always be glowing, ready to heat up again at a moment's notice. Her great glands throbbed slowly, languidly, reminding Derpy that she would always produce milk and would always feel full, but her breasts were pacified for now, no longer demanding to spill gallons of her thick cream just to show that there was no end to her bounty. The fullness she felt now wasn't desperate engorgement but the reassurance that she could have kept going for hours or days if she had wanted to.

Slowly, Derpy got up. "You're so good to me." Seeing Berry act like something of a put-upon caretaker had enhanced the experience, they'd have to revisit that idea in the future.

"Heh." Berry shrugged, suddenly bashful. "I had fun too ... anyway, y'think there's an employee restroom we could use? You lookin' like someone tried to drown you at a dairy farm might get us an in." She hadn't stayed wholly dry either, but her backpack had proven to keep its contents secure in the past, so at least they had a change of clothes.

Berry might have gotten away with letting the sun dry whatever had splashed her, but Derpy was absolutely soaked, including her hair. "We'd best look for someone to ask, then."

Derpy had expected to have a good day, but learning that her boobs would grow if Berry asked it of her, and then Berry playing along with Derpy's public spectacle had left her giddy with excitement for the future.