By the time Twilight made it across teh school, she was a pony again.

It was a subtle thing-- one moment, her leather flats were scuffing over the tile floor, and the next, the sound was replaced by the clop of hooved feet. She paused as soon as she realized what had happened-- and then took a few steps backward. She backtracked all the way to a corner, where she knew she'd been a normal human mere moments before, only to find herself still ponified, still naked.

“Okay, so ... it's not a geographic occurrence.” Twilight murmured to herself, making a mental note. “Which implies this could be a complete planar shift, rather than a localized magic effect. Because every time I've been a pony, everyone else were also ponies, and vice versa for humans.”

Twilight mulled the data over-- and, just to prove her hypothesis, she peeked through a narrow window on a classroom door. Sure enough, there was Mr. Hoofington, now with a muzzle and pegasus wings, keeping a watchful eye on a room full of equally equine students. She even picked out Pinkie Pie's proud pouf of hair at the back of the room. They were all sitting down, thankfully, in the process of taking a test, so Twilight was spared the sight of anything too scandalous. That is, until Pinkie Pie glaced up, her blue eyes meeting Twilight's through the window. Pinkie's wide, infectious smile was unmistakable, even on a short little muzzle. Pinkie sat up straighter and waved eagerly-- which in turn caused her ample chest to jiggle a bit.

“A-hem.” Mr. Hoofington scolded Pinkie, and the pink haired girl went back to her test. Twilight ducked out of sight before the teacher could spot her.

“That was too close.” Twilight said, heart racing. After all, if she were caught peeping in on a classroom, who knows what would happen? No, she needed a safer, quieter place to gather data and compile her thoughts. She snapped her fingers as she realized just where she needed to go: the student lounge! It was just a spare room with a couple of couches and bookshelves, sure, but nobody (nopony?) would ask too many questions about another student hanging out there.

Unfortunately, Twilight soon found she wasn't the only one with that idea.

Two boys (colts?) sat side by side on a couch in the student lounge. Despite their equine features, she recognized the pair from their accessories and hairstyles. There was the taller one, with his dreadlocked hair and Rastafarian hat-- Sandalwood? The smaller one Twilight recognized from his glasses: Micro Chips, president of Canterlot High's AV club (though he now had a blunt horn poking up from his forehead). Apart from their characteristic accessories, the both of them were nude, and happy to show off, by the look of it. The two made an unlikely pair, and yet, they were utterly inseparable, even if they'd been turned to anthropomorphic pony people.

Especially since they'd been turned into anthropomorphic pony people.

Sandalwood put one arm around Micro's shoulders, pulling the bookish young man closer to his broad, bare chest. Micro didn't protest-- in fact, he welcomed the touch. He leaned up to give Sandalwood a little kiss on the cheek, and then slid his hand down his belly, hands going to take hold of Sandalwood's--

“Oh.” Twilight bit her lower lip and flattened herself against the wall beside the student lounge's door. 'Best Friends,' indeed. Soon, a series of soft but rhythmic sighs and grunts began to issue forth from the student lounge. Twilight squirmed, bare back and wings rubbing slightly against the cool metal of a wall-mounted locker. She knew she couldn't look, that she should respect Micro Chips and Sandalwood's privacy ... even if they weren't making any effort to keep things private, apparently. But still, even the playfully passionate sounds coming from the student lounge were enough to get Twilight's vivid imagination to paint lurid, debauched images that made her whole body burn.

Somewhere along the line, Twilight's hands went to her belly, only to start sliding downward--

“There you are.”

Had Twilight been wearing shoes (or much of anything else), the unexpected voice would have scared her out of them. She immediately clasped her hands together for some mild semblance of propriety, then turned to the source of the voice.

“Principal Celestia told me you weren't feeling well.” Nurse Redheart said. She, too, had been ponified like the rest of the school: her pale complexion and neatly tied pink bun were the same, but her practical and shapeless scrubs were gone. Thusly bared, Nurse Redheart was revealed to be a woman in the prime of her life: not as voluptuous as Principal Celestia, nor as toned as Applejack or Rainbow Dash, but a happy medium between. Twilight's eye, in particular, went to Redheart's thick nipples, the coral-pink areolas blending in with the pristine white of her coat. Twilight shook her head, and looked back up to the nurse's face-- somehow, the little white hat Redheart wore looked all the more scandalous, given it was the entirety of her attire.

“Uh. Yeah.” Twilight blurted. “I ... guess I'm just feeling a little lightheaded, and forgot where I'm going?”

“Hm.” Nurse Redheart furrowed her brow. “It's worse than I thought, then. Can you make it to my office?”

“I can do that.” Twilight nodded.

“Good. Follow me.” Nurse Redheart turned on one hoof and started down the hallway, her long tail swaying back and forth over her round, tight derriere. Twilight scolded herself for ogling a school employee-- and then, in a moment of weakness, she peeked back into the student lounge. Micro Chips straddled Sandalwood's lap, facing him, so all Twilight could see was the curve of his bare back and shoulders, along with the hiking of his tail. But by the way they moved, it was obvious they were--

“Ahem.” Nurse Redheart said.

“Coming!” Twilight blurted, stumbling over her own hooves to catch up. “I'm coming! Or! Uh! I mean, I'm ... following you, not that I'm ... you know.”

Nurse Redheart arched a brow, and then wordlessly led on. It wasn't long before she stepped into the nurse's office, with its padded examination table, cabinets full of medical supplies, and vaguely antiseptic smell. Nurse Redheart patted the table, and Twilight obediently sat down on it, crinkling the paper under her bare bottom.

“Tell me how you're feeling, Twilight.” Nurse Redheart said, voice just on the line between sympathetic and businesslike.

“I, um ... I guess I'm feeling a bit distracted, I guess?” Twilight looked down at her hooved feet for a moment. “Like, it's ... it's hard to focus. Really hard.”

“I see.” Nurse Redheart said. The snap of latex gloves made Twilight look up-- Redheart had donned a set of blue examination gloves. Somehow, Twilight found some small degree of satisfaction in seeing that, no matter how crazy things had gotten, at least some people were following basic medical hygiene.

The examination, too, was quite, quite normal. If Twilight closed her eyes, it was just another physical (albeit one without a paper gown). She tried not to squirm from the cold press of the stethoscope to her chest, or wince at the bitter taste of the tongue depressor in her mouth. Then again, the part where Nurse Redheart examined Twilight's wings came as a somewhat novel (and not entirely unpleasant) sensation. Twilight squirmed, wings flaring out a bit, and Nurse Redheart just made a 'hm' noise, and noted something on her clipboard.

“Okay Twilight,” the nurse said, “we're going to take your temperature.”

Twilight nodded, and opened her mouth obligingly.

Nurse Redheart just arched a brow, and then cleared her throat. “We're going to need the most accurate figures we can get, Twilight. You know that.”

“The most accurate?” It took Twilight a moment to figure out what Nurse Redheart meant-- though once she did, her cheeks went scarlet red, and a fresh thrill coursed through her body. “Do you mean--”

“Anally, yes.” Nurse Redheart opened a drawer and took out a long, thin thermometer. “You can lay on your side, or bend over the edge of the examination table, whichever's more comfortable for you.”

“Oh. Um. Okay. If ... you think it'll help.” Twilight murmured, and then positioned herself as directed, settling her hooved feet on the tiled floor as she leaned over. Twilight bit back a moan when her swelling nipples brushed the rough paper of the table.

“Hike your tail up, please.”

Twilight obliged, almost instinctively. She'd almost gotten used to the prospect of roaming around nude-- but then and there, she was even more exposed than before. The cool air of the nurses' office washed over Twilight's most intimate parts-- though what made her shiver was the realization that Nurse Redheart could see everything.

And, at that moment, Twilight wanted her to.

She laid there for a long, long moment, clutching the edge of the examination table. The heat between her legs was almost unbearable as she waited, offering herself to Nurse Redheart, to anyone who might walk by.

Frustratingly, maddeningly, Nurse Redheart didn't take Twilight up on her instinctive offer. Instead, she was all medical professionalism as she slid the thin, lubed thermometer into Twilight's ass.

Twilight gasped at the feeling: cold, strange ... but not entirely unpleasant. She managed not to grind herself back against the thermometer, but just barely. It didn't take long, however, as Nurse Redheart soon pulled it out of Twilight and held it up to the light to take a reading.

“Hm. Just what I thought.”

“It is?” Twilight Sparkle looked over her shoulder, still bent over.

“Honestly, I'm surprised you didn't notice yourself. Slightly elevated temperature, heightened nervous response, rising energy levels ... tell me, Twilight, when's the last time you had an orgasm?”

“Uh.” Twilight's cheeks burned hotter, and she bit at her lower lip. “This morning?”

“What time?”

“Early? Like ... I dunno, five-thirty ish?”

“Five thirty?” Nurse Redheart said, and looked to the clock. “I'm surprised you can even talk at this point. You should know how important proper sexual exercise is to your health, now that you're Eighteen. Everypony's a little different, but you should try to reach climax at least once every few hours, just to let out all that sexual energy. Think of it as a ... safety valve, of sorts, to keep your body from overloading itself.”

“I ... must have forgot?” Twilight offered. “I've been really busy lately.”

“Well, you're not forgetting now.” Nurse Redheart said, stern. “The good news is, after a proper orgasm or two, you'll be right as rain.”

“Oh.” Twilight shivered, and hiked her tail up higher. “Are ... are you going to--”

“If you like.” Nurse Redheart said. Her eyes fixated on Twilight's offered derriere with something more than professional interest.

“I ... I'd like that.” Twilight said. The heat in her cheeks paled in comparison to that between her legs, and she found herself sliding her hooved feet a little wider.

“Turn around and lay back on the table.” Nurse Redheart said. Twilight obliged, the simple, gentle direction making her heart beat faster. Facing Nurse Redheart was a delight in and of itself, as it allowed Twilight to look upon Nurse Redheart's beautiful body. Twilight bit her lower lip, wondering just what it would feel like to run fingers along that pristine white coat, or to close her lips around one of those pink nipples.

“Hold still.” Nurse Redheart said, placing a firm hand between Twilight's breasts, easing her to her back. Her other hand, still wrapped in blue latex, ran up the inside of Twilight's thigh, earning a helpless moan from her.

Twilight opened her mouth to say something, anything-- only to have her words trail off into a giddy “Oh!” once two of Nurse Redheart's fingers pushed into her. Relief washed over her entire body at the sexual contact-- though it soon kindled into further lust still.

Nurse Redheart was ready, however-- as she wasted little time in curling her fingers at just the right angle, seeking out Twilight's most sensative parts. Twilight bucked at the jolt of pleasure-- and then kept on working her hips upwards as Nurse Redheart got to 'work,' methodically flexing her wrist and fingers, building up both force and speed as she went on. Each push of those fingers made lewd, wet sounds-- which were often drowned out by Twilight's lewder-still moaning.

Even if Twilight hadn't grown progressively hornier and hornier over the course of the morning, she wouldn't have lasted long beneath Nurse Redheart's professional touch. All it took was a graze of the nurse's thumb over Twilight's clit to set her off, an electric thrill coursing through her body. Twilight gasped for breath as her body writhed in pleasure-- Nurse Redheart was forced to lunge forward and grab Twilight to keep her from rolling off the narrow examination table.

Twilight moaned again at the feel of warm, soft flesh against hers-- she instinctively leaned up, pressing her lips against Nurse Redheart's. Kissing with an equine muzzle was just as strange as she'd remembered-- but even more enjoyable. She pushed her tongue awkwardly into Nurse Redheart's mouth-- only to have the nurse once again place a firm hand on Twilight's chest as she pulled away.
Nurse Redheart laughed a little bit, and took a step back. “Feeling better?”

“I ... uh ... “ Twilight blinked a few times, staring up at the ceiling tiles. She took a mindful moment to be aware of her (naked, winged, and half-equine) body ... and came to a realization. “Actually ... yes. I mean, that was nice. That was great.” She sat up, stretching her wings out. “I guess I'm feeling a little, uh, clear-headed, now? Not that I wouldn't mind, um ... reciprocating.” Twilight unconsciously licked her lips as she sized up Nurse Redheart.

“I hate to disappoint, but I'm afraid that will have to do for now.” Nurse Redheart said, even as she panted slightly, regaining her breath after the kiss. “After all, if I ... fully indulged myself with every student who came in with raging hormone levels, I'd never get anything else done.”

“Oh.” Twilight's wings and shoulders both drooped.

“But, if you're still feeling ... distracted after school, I'll be more than happy to assist. Though to be honest, I don't think you'll need it. I've seen how close you and your friends are.”

“Oh. Uh. Right.” Twilight said.

“Get yourself cleaned up, and you're good for your next class. Just make sure you have at least one orgasm after lunch, okay?” Nurse Redheart handed Twilight a towel, and peeled out of her blue examination gloves.

“At least one.” Twilight repeated. She managed to clean herself up with a minimum of awkwardness, hoping to get herself from 'lewd' to just 'tastefully nude.' “Got it.”

With that, Twilight bent over to pick up her backpack-- only to jump at a sudden, almost deafening clap of flesh on flesh, followed by a not-unpleasant stinging in her freshly-smacked rump.

“Sorry, couldn't help myself.” Nurse Redheart said. “Now get going, before I can't help myself more.”

“Honestly, I really wouldn't mind if--”

SPANK!

“I'm going, I'm going!” Twilight squeaked, and stumbled out into the hallway. The door closed behind Twilight with a heavy, final sound. Twilight rubbed at her stinging cheek-- and, again, too curious for her own good, she peeked through the window for one last look at Nurse Redheart--

--only to see the nurse brushing a bit of lint from her dress.

Twilight blinked and shook her head, just to make sure. But yes, there was Nurse Redheart, completely dressed, completely human, completely normal. Twilight looked back down at herself once again, verifying the same. Hooves gone, shoes (along with the rest of her outfit) back.

Twilight groaned, though in regular frustration as opposed to the sexual kind. She took off her glasses and rubbed at the bridge of her nose, trying to make some sense of just what the heck was going on. There were just too many variables to keep track of, too many unknowns to question. But, even still, Twilight could at least make two preliminary conclusions.

She'd have to make the 'switch' to the sexy pony people version of reality at least one more time if she was going to figure things out.

And she was looking forward to it.