Daytrip to Canterlot

Berry Punch was having a great day, and not just because they'd managed to freak out a bunch of strangers. She knew pretty well what Derpy looked like when she was overcome with lust and/or cumming her brains out, so she'd immediately noted the gratitude and delight the pegasus had felt for Berry playing along.

Frankly, the fact that the world's randiest pony was in love with her, of all people, had always seemed like proof to Berry that the universe was ultimately random. Although, according to Derpy, she'd been nursing a crush on Berry since before her boobs and her libido started growing.

Of course, she'd correctly predicted that Derpy would rely on her in Canterlot. They'd been holding hands since they left the station behind, because it had at least some grounding effect on the other mare. There were a lot more people in the streets than in sleepy Ponyville, and they'd barely been out of the train station before Derpy was obviously getting fired up again, although not yet to the degree that a stranger would recognize the signs.

Derpy had her free left arm crossed across her stomach so she could idly fondle the bottom of her right boob in a slightly less obvious manner than if she'd just reached up and played with herself. She'd never tried very hard to lose the habit of absentmindedly touching her own boobs, so getting used to doing it with a little bit more subtlety had been a success.

While Derpy tended to point to the fact that she didn't strain to carry her huge knockers around as proof that she was meant to have them, Berry was more impressed by how well Derpy tended to function in her daily life despite her insistent libido. Berry didn't have the pegasus' boob insights, but in her experience, Derpy's tits wouldn't run off the rails overproducing for most of the day, unless the mare specifically started fantasizing about it, and Derpy generally had enough focus for that.

Still, Berry did have a likely spot for a break in mind, just so Derpy could blow off some steam before the palace tour, so staying calm and respectful the whole way through was at least theoretically on the table. Although if people at the palace looked too obviously scandalized to see Derpy jiggle and wobble along, she might just decide to make a real scene, give them something to be shocked about.

"So," Berry picked a harmless topic. "I figure since Pinchy is still obsessed with trains, we could look into model train sets. Uh, the nicer, hobby stuff." She assumed her daughter would have already asked about that sort of thing if Ponyville's toy store were a little less provincial.

Derpy smiled at her. She was slightly flushed and her desire was obvious, if currently unimportant. "Aren't they a bit young for that? I saw a real nice set-up in a display window in Manehattan once."

Berry shrugged. "Well, the tracks and trains bit seems simple enough. The girls got steady hands and might like a bit of responsibility for fragile stuff. We shouldn't compare to professionally done setups, yeah?

"Right," Derpy allowed, but she still looked somewhat dubious.

"Besides, maybe I ought to pick up a hobby anyway," Berry explained. "Something I can do with the kids."

"Hmm, sounds good." Derpy could relax perfectly well by gazing into her own cleavage and spacing out, so she probably hadn't considered a hobby for herself, although she was always in favor of shared activities. "Space might be an issue."

"True. I've actually been thinking of making the attic livable," Berry remarked. She was a quick study when it came to working with her hands and liked taking care of their modest house.

The set of stairs to the attic was steep and narrow, Berry thought that very soon Derpy would struggle to fit, but since she could fly, they might just knock a wide enough entrance into one of the gables in an emergency, maybe a little balcony. Of course, explaining that sort of workaround would just get Derpy more worked up. The pegasus loved the idea of having the world adjusted around her.

"We could put in a small bathroom, I think Sparks would love to have her own little apartment if she wants to stay with us," Berry continued to throw out ideas. "We could use her old room as some kind of hobby or play room, that seems like a better idea than just having a guest room or something."

"You just don't like visitors," Derpy accused, sounding amused.

"We got a perfectly fine couch if someone wants to crash. Lyra and Bons' place is barely smaller and they got no kids." Berry didn't think Ponyville was short on hospitality, so her own dislike of hosting people overnight seemed well compensated for. "Anyway, I just want the girls to have the option of pursuing stuff that interests them at home."

Derpy nodded, squeezing Berry's hand briefly. "I get it."

They spent some more time in conversation like this as they moved through Canterlot, getting some hayburgers for lunch. Avoiding dairy products in their food was a sensible precaution, even if Derpy didn't always get herself riled up with fantasies of dominating the dairy industry all by herself.

At one point, Berry successfully distracted her partner from noticing an inactive fountain with an empty basin. That sort of sight tended to really get Derpy going. Berry didn't begrudge her that, but there was a schedule to keep and she had her own idea.

"I'd like some shirts with text on them," Derpy stated without prompting.

"Yeah, like what? 'Unlimited Refills'?"

"Mhmm." Derpy hummed pleasantly. "Good idea. I was thinking 'They'll never be this small again'. I kinda missed being able to say that, earlier." She fondly patted the side of her rack.

Berry knew that it was one of Derpy's favorites to tell others or herself 'they've never been this big, but they'll never be this small again'. Berry chuckled. "Might start to sound threatening, the size you're at." She suspected many townspeople back home still told themselves that surely, Derpy would stop growing now. Berry liked to think that Derpy's size would be whatever her conscience allowed. It was fairly evident by now that biological limits didn't mean much.

Derpy just smiled before changing the topic again. "What'd you plan next?"

"One of the observation decks," Berry replied. Since Canterlot was built fairly precariously into a steep mountainside, there were no shortage of locations where residents and tourists alike could enjoy a view of the countryside below. "Got it on good authority that it's one of the less busy ones."

"I rarely bother to fly high enough for this kind of view," Derpy noted. "You'll like it, I think."

"Even if the view was an old hat to you, I was planning to make it worth your while," Berry stated with a grin.

"You're always full of good ideas," Derpy purred before putting a bit of a skip into her walk to make her breasts wobble more.

"I try," Berry nodded. "You might have mentioned something like that before, but I think we really should start hanging up mirrors. Big ones on the walls, small ones up in the corners, might help you maneuver around the house in the future."

Derpy giggled. "If I get too used to that kind of aid, I'll just keep bumping into other ponies or things when I'm out of the house."

"How awful." Berry knew full well that Derpy would get a thrill out of that every time. "Well, I figure you can afford to go bigger. Sparkler's gonna stick around for a few years yet and the other two are getting old enough to get them more involved with the chores." The opportunity costs of having absurdly large breasts were something they didn't much talk about, because Berry wouldn't really mind Derpy being less able to help around the house over time, and it wouldn't make the pegasus worse at the emotional work of being a mother, which was the important bit since the girls were no longer helpless.

"If you're sure." Derpy managed to avoid sounding too eager. She always wanted to be larger. Berry had proposed some real absurd sizes, and while Derpy was obviously aware that such things weren't likely because she had neither the time to pursue them nor the will to occupy large areas with mountains of boob where it would cause problems for other ponies, she never had a gut reaction that said 'too big' or even 'big enough'.

"Sure I'm sure." Berry looked around. There were always ponies staring at Derpy. "Canterlot folk are awfully polite. Figured by now someone would have come up to hit on you."

Berry wasn't 'tall for a mare', she was just tall, and while she wasn't as naturally gifted as some earth ponies, she had a broad frame and worked out to keep her strength up. It wouldn't surprise her if most of these locals took a look at her and developed an urgent need to not get in her way. If it wasn't for Derpy's huge tits, Berry would be the memorable one of the two. She'd never cared about being conventionally attractive, that sort of thing hadn't had much survival value when she'd been growing up. That she was apparently Derpy's type had just been fortunate coincidence.

Derpy rolled her eyes. "In public, in the middle of the day?"

Perhaps neither Derpy nor Berry were particularly well informed about courtship behavior. They hadn't exactly had any sort of storybook romance themselves – they'd been friends for years and moved together for practical reasons before Derpy had mentioned her crush. They'd grown comfortable together.

"Maybe not," Berry allowed. "Listen, I know you love pretending like your jugs are takin' advantage of you, but maybe you'd enjoy running roughshod over some meek sop. Plenty of ponies would call you 'mom' before drinking if it meant they get their hands on the greatest tits in the world for a few minutes."

Derpy blushed. "Well ... maybe. Sometimes I think it would be nice to hear people talk about them in that tone they use for the Princess." According to Derpy, Cloudsdale had a downright annoying quantity of statues, or cloud sculptures really, depicting Celestia. The mail mare had never been particularly worshipful.

"They're Derpy's boobs!" Berry tried to affect a tone of breathless awe.

"Y-yeah. Like that." Derpy bit her lip before smiling at Berry with barely restrained joy.

It was a good way to be looked at.

Berry changed the topic as they approached the observation deck. "Anything else you'd like, next time you feed someone?"

"I could ask you the same," Derpy replied. Her milk had changed some ponies, bigger boobs being most common.

Berry shrugged. It wasn't the first time it had come up. "I'm not unhappy with my looks. Besides, why would I want to change, given the way you always look at me? Clearly I'm perfect for you." She had a bit more padding than strictly necessary, made her look slightly less fit than she was. Berry couldn't tolerate being hungry and probably ate a little too much even for someone who worked out heavily.

Derpy blushed some more and nodded. "I wouldn't mind wider hips." She shrugged. "I mean, I'm fairly close to ideal in that regard, and I wouldn't want my ass to get stuck in a door frame, but a bit more 'round the back would feel nice, don't you think?"

"Well, I hadn't thought about it before, but you're not wrong," Berry agreed. Derpy didn't look nearly as slender as she had when they first met. She'd put on muscle to support her growing boobs and her hips, thighs and rear had slowly grown as well. Berry had some difficulty guessing what Derpy would consider her ideal shape, since the pegasus' standards were so distorted by her huge tits. Sure, not getting stuck in doors was a clear statement, but while Derpy certainly had motherly hips, she was pretty far off from that, and it remained to be seen how close to it she would want to be. "Well, try to keep it in mind the next time you really grow. Obviously your body is pretty obliging," Berry reasoned.

"I'll try," Derpy agreed, although without the certainty she always had regarding her breasts.

"Great. And if it's any consolation, I do hope for good health and long life whenever I have a drink from you." Berry grinned. "Just in case you turn out to be some immortal Princess of Tits, I wanna be along for the ride."

Derpy nodded. "Good." She started rubbing a hand along the underside of one of her jugs, smiling proudly.

Eventually they reached the observation deck, which wasn't empty but not particularly crowded. The railings were fairly tall and topped by an inclined band of metal embossed with a relief of the landscape below, including names of visible towns and terrain features. Berry maneuvered Derpy to the railing and made a show of 'helping' her rest her rack on top of it.

"The view really is nice," Derpy commented. She grasped the sides of her breasts to adjust their position slightly. "You're always so thoughtful, Berry," she sighed, always enjoying being touched. The way Derpy talked about her sensitivity, the parts of the relief her boobs covered were probably clear as a picture in her head.

Berry stood behind the shorter mare and wrapped one arm around Derpy's midsection. "Yeah." She smirked. "You wanna be visible from up here eventually? Pair of hills in the landscape, hm?"

Derpy nodded lazily. "Sure," she paused a moment. "Nice ... intermediate size to maintain. Just long enough for everyone to convince themselves I'm done."

"Hm. Might not happen. They'll probably form a whole department just for watching you, and for figuring out what all that milk does to the countryside." Berry liked to think she'd gotten pretty good at painting scenarios which would excite Derpy. Attempts at quantifying or even controlling her seemed to strike a particular chord with her.

"Go on, please."

"Well, maybe someone would let slip how your milk's been getting into the groundwater and the soil, indirectly helping to feed ponies. That'd light a spark in your head, get you growing enough to set off the alarms."

Derpy sighed pleasantly as she crossed her arms atop her rack and leaned on it, probably just to do something no observer could copy, since it didn't look that comfortable.

Obviously there was a mental component to Derpy's growth, so far she had to at least see someone drink her milk for her boobs to react, otherwise she would have grown quite a bit in the days after first donating her milk to the hospital. Not that either of them were concerned with these details when it came to fantasies.

"Anyway," Berry spoke quietly. "I've heard there's a decent chance to see the Princess herself on these tours. I figured you'd like knowing that someone like that knows who's got the biggest jugs in the world."

"Oh yeah," Derpy nodded eagerly. "Bet she's never seen anything like mine before." She spoke with conviction, despite the fact that an immortal like the Princess must have seen a great many weird things.

"I don't know," Berry trailed off, pretending to be doubtful. "Maybe she's not gonna react at all. Y'know, 'huh, these are big but I've seen bigger and milkier.'"

Derpy reacted with a sharp intake of breath. "I'm ... hff. Not a fan of the idea." She squirmed a little against Berry.

Berry reached forward and brushed a hand over one of Derpy's nipples. As she'd expected, they were rock hard, tenting the mare's shirt prominently. To her credit, Derpy wasn't leaking yet. Berry looked forward to what might happen later, now that she'd planted the idea that the Princess might see and be unimpressed by Derpy's rack.

"Don't want her to overreact the other way, do we?" Berry teased. "Put you in a lab, try to figure you out?" It seemed reasonable to expect that eventually someone would want to figure out how a pony who wasn't even a unicorn could create so much from apparently nothing.

Derpy hummed before saying, "I can't be contained." She sounded certain, but followed up the statement with a 'huh' as though the thought had been unexpected. Some boob feeling, probably.

"That sounded less threatening when you were talking about bras." Berry knew that Derpy didn't favor destructive fantasies, even when imagining totally absurd sizes. Derpy didn't dream about smothering entire cities, but she enjoyed the idea of being so vast that ponies settled on top of her mountainous tits. Still, clearly they'd have to further explore ideas involving constraints imposed by others. "Should I put together some kinda mock door frame for you to get stuck in?"

"You read my mind," Derpy praised, arousal clear in her voice. "I really felt like ... like I could have just burst out of those doors earlier." She reached forward to start pulling up her shirt over her nipples. "Gonna need ... I'll need release before the tour."

"Glad you decided not to cause property damage, then." Berry chuckled, using her right hand to tweak one of Derpy's nipples, while she snuck down her left to the base of Derpy's left tit. "Bursting out of physical restraints is probably gonna turn out to be amateur stuff."

Derpy had always been able to expand to some degree simply by getting her jugs riled up and eager to spray milk, then denying herself for a while. The growth on Berry's demand on the train had been something new, and she was eager to see how her lover's boob powers and her control developed.

"I think you could go more abstract," Berry continued. "Maybe you could grow out of some situation you just feel stifled in. Formal dinner or some other fancy occasion, maybe." It wasn't one of her best examples, really, because Derpy enjoyed being inappropriately large for the current location or situation, but also because she was selective about when and where she'd cause a scene. Spicing up something mundane like a train ride was different from making a mess at an event other ponies might consider a rare treat to be at.

"Heh. What ... what if I felt limited by linear time?" Derpy started releasing thin arcs of her milk. They'd probably be scattered into individual drops by wind before landing anywhere. "You'd tell me if you remembered me bein' h-huge already when we first met?"

"Not bad," Berry noted her approval. Derpy used to rely heavily on Berry to come up with outlandish fantasies to get her hot, but nowadays she readily came up with her own ideas. Berry rewarded the other mare with a tug on her right nipple while digging her fingers into the underside of her left tit, right by the base. After years of exploring Derpy's body, that combination was the best way to get the pegasus to climax quickly and repeatedly which Berry had discovered so far.

Derpy bit back her moans as her milk sprayed off the viewing platform. Actual milking motions weren't necessary, really. The pegasus' body barely needed permission to let down milk, let alone any active encouragement.

"You could do all sorts of crazy stuff with time travel, but most of it seems ... too sneaky?" Berry gave Derpy's nipple a teasing pinch, causing a brief increase in milk flow. Her boobs reacted even to such a small, implied attempt to control them. She felt Derpy shudder in pleasure. "We'll have to collect some ideas."

"S-sure." Derpy stifled another moan, but collected herself reasonably quickly. It was just routine maintenance, after all.

To Berry, having to masturbate and milk herself several times a day seemed like it would be a huge hassle, but she was good at not caring about things that didn't directly affect her, and it was pretty fun to send Derpy spiraling from 'randy but functional' to overwhelmingly aroused with words or well-practiced touches. And even years after her boobs had started growing, Derpy still acted smug like she was getting one over everyone else whenever she had to cum or express a bit of milk during the day.

She doubted other ponies would continue to be as kind and thoughtful as Derpy with that kind of body. Or maintain the restraint necessary to make their little trip a special treat instead of just a day in the life.

"You good to go, then?"

"Hm." Derpy nodded. Toweling off her tits a little to avoid getting her shirt any wetter was just another part of the routine – for those special occasions were it seemed sensible. After all, Derpy was clearly immune to any discomfort wearing a wet shirt might cause, and liked to parade around reminders of her productivity.

"You gonna keep it together at the palace?" Berry assumed she would if everything went off in an ordinary fashion. If they didn't actually get to catch sight of the Princess, Derpy might not want to ruin the guided tour for other ponies.

"We'll see!" Derpy smirked as she turned, smugly checking for anyone who might have watched their little milking session. She started moving, striding really, head held high, back straight and tits thrust out.