There's a WHATquestria?!

In the calm, quiet town of Ponyville, for once in a long, long time, nothing horrible was happening. No monsters were assaulting the village, trampling the people and the buildings. No dark wizards had usurped the powers over the sun and the moon. Pinkie Pie hadn't even offended any dignitaries by pointing out embarrassing truths such as balding patterns or marital disputes.

The sun, just as big as it should be, just as round as it should be, just as hot as it should be, looked calmly over the sprawling land of Equestria and shone through the stained-glass windows of a gaudy crystal palace towering over the meager thatched-roof cottages and occasional villas of Ponyville.

And deep within, Twilight Sparkle lay on her back in bed, sleepily whinnying, her mouth wide in a drooly grin, as the sun gently attempted to coax her awake through her curtains.

But it would have to try a bit harder, for Twilight Sparkle never had a lazy day - she wouldn't stand for it - and had tired herself out by the previous evening.

She had spent that lovely, free day giving herself and everyone she knew all kinds of things to do. She'd exhaustively measured every room in the castle to better plan out room decor in the future. She'd sent Pinkie Pie on an experimental food lab binge. She and Fluttershy had taught each other some new words they'd never use, like "verecund" and "borborygmi".

"Mmm," she mumbled, shifting uncomfortably. "Rrrgh," she winced, rolling in her sleep. Deep inside her sleepy little pony brain, her dreams of transforming Equestria into a gleaming white future-utopia were cast aside by a massive equid shadow, like a circus stilts pony. The buildings crumbled silently on touch as it slowly, steadily crept after her, even as she fled. It gradually sped up in pursuit. Soon enough, it reached her, and at its touch, she was sucked tumbling into its shadows.

She saw herself falling towards her. Was it a mirror? She crashed through it silently and was startled awake with a gasp, staring at her ceiling.

She blinked, sweating, catching her breath. What the heck is that noise..?! she thought in a panic. Something was... mooing? Making some strange noise from somewhere in the house.

It was distant and at once familiar and unfamiliar. It must have been a living thing. Ghosts weren't real, so that couldn't be it. Oh, she realized with relief, Oh it's just Spike. Was he trying to carry something heavy? That might be it, he often gave it a shot when packages arrived early in the morning or otherwise no one was around to help him. She'd have to go save him from hurting himself.

She stretched and attempted to get out of bed. "Urk," she huffed, having some trouble rising. Her butt felt heavier than usual. After a few attempts, she sighed, then, sweeping the covers off herself magically, forced herself to roll clumsily out, falling off the bed and onto her face with an uncharacteristically deep slap.

"Ooouugghh..!" She felt an immense impact against the area of her waist and a deep, dull pain as she rose slowly and awkwardly to her hooves. Why do I feel so heavy..? she thought. I can't be that tired... She yawned and shambled past her mirror, giving a drowsy nod to her reflection and turning away.

She froze halfway to the door, her dopey smile falling.

She stumbled back to the mirror and stared. Her mouth fell open and her face burned pink.

Ringringring! went five butts somewhere in Ponyville.

Twilight sat uncomfortably at the table, her face itching, looking around at her friends and herself. Specifically, at all of their enormous tits flopped out on top of the Map. Is this what Celestia feels like, she blushed. When I figure out what's going on I'll never ogle your massive boobs again, teacher-god-mom.

She blinked. Okay, that's a lie, I totally will.

Finally, Applejack coughed, her giant udders wobbling in response. "Do ya mind," she blinked with a pout and crossed forelegs.

"I -- s-sorry..." Twilight cleared her throat, tearing her gaze away from Applejack's undercarriage and closing her eyes. Then she opened them again, remembering something else. "... Where's Spike?" she asked, looking pointedly away from the girls and to the corners of the room.

"Where do ya think," Rainbow Dash scoffed. "The same place he always is when you call us all over, hiding somewhere and pawing off. Usually one of the bathrooms."

"What!!" Twilight yelped. "My little Spike?! My sweet little innocent baby boy?!" Oh dear, that wasn't mooing was it, she realized. The heavy thing he was lifting was his oh no.

"Well he can hardly go without for very long with such ample assets, now can he, darling," Rarity crooned absently, focusing her half-lidded eyes on her magic needlework. "He'd explode within a weekEYYAAIIE!" she shrieked as she poked her udders with the needle.

"I find it helps to put some kind of tray over my boobs," Fluttershy advised comfortably.

Twilight swayed back and forth on her seat, a hoof to her temple, summarizing what she had learned today. One, my boobs are huge, she began. Two, all our boobs are huge. She started to feel ill. Three, Spike jerks off to our huge boobs and everyone is totally cool with that. She forced down her gag reflex.

"Twilight, what's this all about," Dash scowled. "You're being even more Twilighty than usual."

"Am I the only one who sees a problem here!" Twilight cried, attempting to slap the table. "Ouuugghh..!" she groaned, having smacked her giant tits instead, and began sobbing from the exquisite pain. I am not a big boob kind of mare, she bemoaned. I'm totally lost on what to do with these things, they're like big round kick me signs.

"No tray can help against doing that," Fluttershy gently scolded. "I thought you usually got up and pulled them back first so that that doesn't happen..."

"Good idea thank you," Twilight gasped through the boob-pain. "But please explain to me what strange force has given enormous mammaries to every mare in Equestria."

"Tittyquestria," Pinkie corrected at once, tilting her head and staring seriously.

"... Whatquestria?" Twilight blanched.

"Tittyquestria, dear, of course, and the Elements of Titty have given us these lovely, full undercarriages," Rarity drawled, now holding her sewing well above her industrial-sized black mams. She paused to give Twilight a concerned look. "Did you hit your head? Are you quite alright?"

Twilight fought to keep her consciousness as dots swam in front of her eyes. Pinkie would never say something like that, she reasoned. And if she did, Rarity would have been outraged. Rarity's always been shy about it because her boobs are pretty big and their dark color against her pale coat is really candid. But they're acting like these gigantoboobs are totally normal for them - even Fluttershy is completely at ease just havin' 'em out.

Her eyes widened in sudden realization. This is totally normal for them, she concluded. I'm in another Equestria. A T... A T-T-T... A "Tittyquestria"..!

She rapidly extrapolated, which was her favorite way to cope with unpleasant information. Given the name, this version of Equestria probably features gigantic, grass-tickling mammary organs on literally everyone applicable. That's what the "Elements of Titty" are, the boobs are built into the magic just as deeply as friendship is. She slowly breathed in and then out. Not just Pinkie Pie, Fluttershy, Princess Celestia, Chrysalis, Gilda, Mrs. Cake, Fleur de Lis, and... She stopped and blinked. Alright so maybe I already live in a THATquestria, but oh my gosh I can feel them smashing against the table just from their own weight, I feel the air change against my wobbling skin when I breathe, it's so bizarre, is this why Fluttershy - my Fluttershy - is so self-conscious?

"Okay, listen," Twilight started again, more slowly. "Applejack. What did you and I do yesterday?"

"Uh, well, lessee," Applejack put a hoof to her chin to think. "I believe I tole you ta kick my bigguns hard as ya could."

Twilight gaped at her, lost for words.

"But you can't hardly kick fer beans," Applejack continued, "So's we had ta git Rainbow Dash, 'n' I reckon that hurt a fair bit more, but I were satisfied I could take a hit from any threats ta Tittyquestria." She nodded, beaming and proud of herself.

"You have us kick you... there..." Twilight repeated in disbelief, gesturing in the vague direction of Applejack's boobs without looking, "So you can develop boobs of iron?"

"We been at it fer years!" Applejack insisted like Twilight was nuts. "You girls oughta git inta it, you all go down with one lil' tap, 'n' big as we are it's easy as knockin' a barn down..."

"Now let me tell you what I remember doing with you yesterday," Twilight countered. "We worked on the framework for an Oob Portal."

"A Boob Portal??" Applejack tilted her head.

"What -- no!!" Twilight honked. "No, why would you -- As in for Ogres and Oubliettes? Spike plays it, I wanted to make him a dedicated playing space. An Oob Portal!"

The girls furrowed their brows in worry, glancing at one another. Great, that's probably called something stupid and booberiffic in this place, Twilight conjectured.

"And let me tell you something else," Twilight continued, "When I went to bed yesterday, Rainbow Dash was flat, Applejack and I were petite, Rarity was kinda big but not that darn big, Pinkie and Fluttershy were... pretty much just as they are now, and while Spike has always been supremely well-endowed for what is ostensibly a 'baby dragon', I was not aware of him gratifying himself to our bodies!" she summarized, forcing herself to keep a straight, but very red face.

"Twilight," Applejack fretted softly. "Are you okay? We should git you to a doctor..."

"Pinkie," Twilight tried. "Has your Pinkie Sense gone off recently?"

"My biggy piggy jigglies felt real funny on the way over here," Pinkie chirped brightly, causing Twilight to cringe. "And not just because the Mayor has been skimping on keeping the grass trimmed! You know that feeling ya get when it's gonna rain and your tooters feel funny?"

The girls all groaned and nodded in apparent understanding. I will die before I ask my Pinkie if her piggy-whatevers feel funny when it's going to rain, Twilight vowed.

"I got that like times five!" Pinkie put both hooves to her face in horror. "I thought I was gonna need to go milk myself!"

Twilight began to choke and cough. Note to self, don't eat any baked goods in this entire place.

"Also my butthole itched," Pinkie added, a hoof to her chin in thought. "That only happens when interdimensional stuff happens or I have too much pepper."

"Oh my, I always get a terrible itch when I feel something's amiss," Rarity tutted. "What is it about our derrieres and premonitions? Even the boys have it!"

"None-a-y'all believe me when I tell you my ass is tellin' me ta stay out some haunted-ass house 'fer my tits start talkin' ta me," Applejack protested. "You drag me in there and m' butthole seals up like th' Canterlot treasury."

"Did you say interdimensional," Twilight managed. She had changed her position to not have her boobs on the table, giving her room to bury her face in her forelegs.

"Yep!" Pinkie beamed.

"Then this explains everything," Twilight sighed, looking back up. She was relieved that she had probably confirmed what had just happened. She was horrified that she had probably confirmed what had just happened. "I'm not your Twilight."

"Whaa--" came the chorus of confused bimbos.

"I'm a Twilight from a different Equestria," she concluded. "Somehow, my consciousness has been put here in your Twilight's body. I'm now trapped in, um."

"Tittyquestria." The doors opened, and the local version of Starlight sashayed in, big ass and huge tits swaying, magically holding a very embarrassed Spike wrapped up in a towel like a cocooning bug. "And this pervert was watching me shower... again... oughta geld his ass..."

"Please don't," Spike begged. "You tempt me so, it's not my fault."

"Starlight!" Twilight chirped, almost crying with hope. "You've come back to the light in this world, too?" And you threaten Spike with castration in this world, too, she considered with less enthusiasm.

"Yeah..?" she blinked, leaning back.

"Listen, I need your help," Twilight begged. "I'm not the Twilight from this world! I need to figure out what happened and how to fix it! Please tell me you're as good at dark magic as my Starlight is!"

"What kinda shine does she get into?" Starlight asked.

"She once mind-controlled the other girls to be her slaves for an entire day."

"Ooh loons, kinky," Starlight blushed. "I'd never have the courage to just --"

"It wasn't sex!" Twilight huffed.

"Oh," Starlight sighed, disappointed. "Oh, then yeah, I can totally compete with that."

An hour later, Twilight gave one of her trademark frustrated groan-sighs and attempted to flop down onto the floor of the library, in front of the impromptu mirror they were working on.

Slap.

"OUUUUGGHHH..." Twilight withered, curling up and holding her mams with her wings. "How do you girls get anything done with these..!" she sobbed.

"Practice," Starlight responded at once without looking up from her grimoire. It was softly glowing with purple flames. "If it helps you feel any better, our Twilight does exactly what you just did when she's tired enough. You'd think she'd have boobs of iron like Applejack by now, but uh, no. As you can tell, nowhere close."

"I don't understand," Twilight grumbled. "This body has a slightly different magic signature from my own, this implies all Twilights are unique, and I know my own magic signature, we should be able to lock the mirror onto it without a problem!"

"... but that's nothing compared to how our Twilight tortured my super-sensitive tits with black ice for about an hour until I gushed all over her face oh! Uh, maybe there's some kind of interference," Starlight offered. "I mean, you have no idea how you suddenly woke up in this body, right?"

"Right, and I'm presuming that this must be a different universe and not just a bizarre retcon of the one I was already in," Twilight fretted, trying and failing to mentally block whatever that other thing was Starlight said. "If it's the latter I guess I'm screwed."

"No way, why would you be the only one who noticed the change?" Starlight countered. "Our Twilight's gotta be in your world, lookin' for a way back herself. We'll meet her in the middle like building a railroad."

"I hope so," Twilight sighed, carefully getting to her hooves, wincing from her sore boobs. "I'll never understand why Rainbow Dash is so jealous of these things."

"Rainbow Dash is jealous..?" Starlight asked, raising an eyebrow.

"Ours is flat, but Fluttershy and Pinkie are just as big as your versions."

"That makes much more sense, the whole faster than sound thing. Wait, Fluttershy too?"

"Yeah. Is that weird..?" Twilight tilted her head.

"Pinkie I can understand, but shouldn't all pegasians be as... javelin-shaped as they can get away with?" Starlight blinked.

"Well, most of them are pretty slender..." Twilight admitted. "But the mares in Fluttershy's family, uh, aren't. She's always been really self-conscious about it, because it affects her flying and she was bullied a lot in flight school. She doesn't like when ponies stare or make comments about it."

"Fluttershy doesn't want you to notice her tits?" Starlight doubted. "But she's like, the boob guru of Ponyville!"

"The what."

"All the mares and older fillies look to her for advice," Starlight clarified. "She knows proper gaits, common obstacles, massage techniques, and even makes bras! Well, mostly for the older mares."

"Don't tell me Granny Smith has --" Twilight started with a hoof raised, then stopped, nodded, and put her hoof back down. "Forget it. Blindfold me whenever we leave the castle. But since big boobs are... uh... not as common in my world, the mares who have them are more bashful about it."

"What about me?" Starlight raised her chin primly. "How do I stack up in your world of titty inequity?"

"You're... okay," Twilight offered uncomfortably. "Above average."

"I'll take it," Starlight nodded, and continued to consult the grimoire.