“Hello! Is anyone here?” Fluttershy called, the mare awkwardly pushing her way into the empty library, the door squeaking loudly on its rusted hinges. “I got your message to come early, is there a problem with the lesson plan?”

When no one answered her, the pegasus stepped inside and pushed the door closed behind her. She then looked around, trying to locate any sign of either denizen who called the tree home. Everything was immaculately well kept as per usual, and she couldn't hear anything out of the ordinary. There was only the faint whistle of the wind and the odd conversation carried upon the breeze.

“Odd,” Fluttershy muttered to herself.

Peeking into the kitchen she found that it was empty, with the only thing out of the ordinary being a couple of dishes in the sink. She moved onto the stairs but heard the thump of something heavy falling followed by a muttered curse. The sound seemed to have come from the basement, so after a bit of courage gathering, Fluttershy made her way in that direction.

“Hello? Twilight? Are you down there?” asked the pony in a nervous, halting tone.

“Oh uh yeah! I’m just downstairs!” called the familiar voice of Twilight.

With her heart now beating its normal pace, Fluttershy pulled the basement door open and looked down. To where she found Twilight had constructed a miniature classroom, though there was only a single desk near its center. The unicorn herself was studying the board closely and had combed her hair into a slightly more professional style.

Noticing that everything seemed normal, Fluttershy made her way down into the basement. She tried to ignore the faint jiggling of her own butt cheeks, but it was difficult given their sheer size. Even clenching slightly didn't stop them from clapping together on occasion, bringing a blush to the pegasus’ face.

Twilight didn't seem to notice this however and continued studying the board until Fluttershy reached the bottom. Then the unicorn turned, a smile on her slightly blushing face.

“There you are Fluttershy. Sorry for noone meeting you at the door but I sent Spike on some last-minute errands and got caught up with a spell,” Twilight explained, gesturing to the formula-covered blackboard nearby.

“Oh, that's no trouble Twilight. What kind of spell were you working on?” Fluttershy inquired.

“Uh, it's nothing,” Twilight dismissed. “Just a little alteration spell. The only reason it's so difficult is its semi-permanent nature, which complicates the casting slightly.”

“That's good. I think,” Fluttershy murmured absently.

“Yes, well. Anyway,” Twilight cleared her throat. “I was hoping you would be able to help me with something.”

“Did you want to go over the lesson plan again?” Fluttershy inquired. “I know you’re nervous about teaching but we’ve gone over it a few times and I’m sure you are going to do a good job.”

Twilight coughed into a hoof, a blush crossing her face. “No, it's not that, well not exactly. Look, I just wanted to ask you a few questions is all.”

“Oh um. Okay, go ahead,” Fluttershy encouraged.

“Well you’ve been doing lessons on animals for the school for a few years now, right?” Twilight pressed.

Fluttershy nodded. “Yes, for almost five to be exact. I love being able to show all the fillies and colts that you don't have to fear the forest if you are considerate. They used to be so terrified of the Everfree but now I think they have the opposite problem now.”

“Ahh yes, little Emerald Jewel and her quest to make a manticore her pet. I heard about that,” Twilight murmured.

“Oh, it was dreadful. I’m glad she ended up running into old Sting Spike though,” Fluttershy continued. “He's as territorial as they come, but views ponies like cute little pets.”

“That would make a good research project but that's not where I was going with that question,” Twilight stepped forward. “I was hoping you would help me learn how to deal with foals.”

“Well just be patient, and kind but not too patient. Otherwise, they’ll distract you a whole bunch in order to avoid the lesson,” Fluttershy blushed, and pawed at the floor. “Which might have happened, a few times.”

“I don't want that to happen to me, but I also worry about what may happen if I get a bad kid in my class,” Twilight professed in a low, guilty tone.

“Oh, Twilight. There is no such thing as a bad kid, only bad days,” Fluttershy paused. “Though I suppose there are some exceptions to the rule.”

“It's those exceptions I’ve been worrying about,” Twilight professed, stepping closer and looking Fluttershy in the eye. “Which is why I want to ask for your help.”

Fluttershy smiled sheepishly, taken aback by the sudden closeness. “Of course Twilight, whatever you need. I’d be happy to help,” Fluttershy replied after a short pause.

“Perfect!” Twilight proclaimed. “I wanted to really get in the mindset of the student-teacher environment so I grabbed you a uniform that I had lying around the library.”

Fluttershy looked over to the desk, which briefly lit up with Twilight's aura before the top lifted. Revealing what looked like a uniform made for a male attending a rather expensive private school. There was a white undershirt, a blue sweater, complete with tie, and a pair of gray slacks that looked two sizes too small for Fluttershy.

“B-but that's a colt’s uniform,” Fluttershy murmured in shock.

“Oh yeah. You don't mind though, right? I mean, it's just for pretend,” Twilight pressed, waving the ensemble in front of Fluttershy’s face.

The pegasus blushed harder than before, her back legs clamping tightly together in response to the sudden flood of arousal. The mere thought of wearing something like that made erotic ideas flit through the pegasus’ mind. She wasn't sure how Twilight had figured out her secret kink, but Fluttershy was determined to not let it slip that she was turned on.

“O-okay,” Fluttershy stuttered. “I mean, it's just some clothes, right?”

“Of course. It's just some clothes that will help us get into the mindset, and really help us create a believable scenario,” Twilight pressed, squeezing Fluttershy around the shoulders.

“R-right. Just a second,” Fluttershy muttered.

Twilight took a step back and extended her hoof. “Of course. Take all the time you need Fluttershy.”

The pegasus clenched her jaw and nodded, taking the levitating set of clothes from Twilight's magic. Fluttershy immediately found that they were as comfortable as they looked, causing her blush to grow larger still. Determined not to let Twilight discover how aroused she was becoming, Fluttershy took a few steps away.

She then laid the clothing on the desk, and grabbed the pants first, stepping into the brown slacks. With a twist and a pull, she managed to mostly squeeze into the trousers, though not all the way. Stuck at around the midpoint of her flanks, the wide-hipped pegasus found her efforts stymied no matter how hard she tried.

“Need a hoof?” Twilight offered.

“N-n-no,” Fluttershy grunted, pulling several more times before giving up. “Okay, maybe a little bit.”

“It's okay Fluttershy. There's nothing to feel embarrassed about. You just have a naturally curvy, and quite attractive figure,” Twilight remarked.

Fluttershy was still reeling from the compliment when Twilight stepped forward, placed her shoulder against Fluttershy’s chest, and reached behind her. The unicorn’s hooves gripped the top of the trousers, and with a heave, she pulled them over Fluttershy’s momentous butt. The effort was considerable, but somehow the cloth managed to stay in one shape without even ripping in the process.

For a moment, Fluttershy simply stood there, confused and shocked by the fact that the pants fit. Not well, they hugged her generous curves a bit too tightly and squeezed her ass like a cheap date. Yet the fabric stayed in one piece and even allowed her enough range of motion to move around.

“Is it good?” Twilight asked, her muzzle mere inches from Fluttershy’s own. “Does it need another tug?”

“N-no,” Fluttershy murmured. “It's good.”

“Ahh good. For a second there I didn't think those pants could contain your beauty,” Twilight remarked.

Fluttershy blushed even harder, her face almost beat red at that point.

Twilight didn't seem to notice this and had taken a few steps away, prompting Fluttershy to continue. Pulling the undershirt over her head, the pegasus tugged it into place, securing it into the hem of her pants. It was tight, but with that done, she put on the final article of clothing before securing the tie around her neck.

“You sure did that quickly,” Twilight remarked.

Fluttershy nodded mutely. “Rarity made me wear a bunch of very different clothes when I was modeling for her. That's all.”

“Well, like everything you wear. You pull it off expertly,” Twilight exclaimed.

“T-thanks,” Fluttershy murmured nervously.

“Right, so,” Twilight began, walking over to the blackboard. “I was going to launch into a lecture on magic, and I want you to pretend to be the bad student who disrupts the class.”

“I can do that,” Fluttershy exclaimed.

“Great. Just do your best, and feel free to interrupt me at any time,” Twilight offered, gesturing to the desk.

Taking the hint, Fluttershy seated herself in the available chair with some slight difficulty. Her prodigious posterior only barely fit into the seat, requiring a bit of force to sit properly. With that done, Fluttershy did her best to ignore the strange pleasure of getting her butt squeezed, and looked up at Twilight.

“Okay. So we're going to start with a quick rundown on the various equations necessary to cast a proper physical alteration spell,” Twilight began.

Fluttershy watched as the unicorn turned the board over to reveal that someone had drawn a realistic dick on the other side. Colored purple, it even sported several immaculately recreated veins, and a flaring head nearly as thick as Fluttershy’s hoof. The image was so life-like that Fluttershy could have sworn it was a picture, rather than a simple chalk drawing.

The sight immediately set Flutteshy’s thoughts swerving off course, and quickly landing in the gutter. Images of the previous night’s events flashed through the young pegasus’s mind, making her grow strangely warm. She squeezed her legs together, and tried to will away the growing arousal, but it was a struggle to do so.

Being complimented always sent her heart a flutter, but receiving such kind words while wearing a stallion’s clothes amped that up considerably. Add that on top of having her butt trapped within the tight confines of both the chair and her pants and it was a recipe for disaster. Already Fluttershy could feel her love canal begin to grow moist, her feminine juices starting to soak the fabric.

“Fluttershy, you're supposed to distract me and pretend to be a bad student,” Twilight remarked.

“Oh um… this is boring,” Fluttershy murmured guiltily.

“That it may be, but it's very important to know all the boring math before you cast an alteration spell,” Twilight continued. “If you don't take these things into account then you may end up harming yourself or others.”

“O-okay,” Fluttershy whispered mostly to herself.

“Perhaps this is all a bit too dry,” Twilight remarked. “Maybe a demonstration will perk your interests.”

Fluttershy was about to reply with something she hoped was bad enough, but was halted before she could do so. The heavy thump of a hoof hitting her desk stopped her train of thought and drew her eye to Twilight's crotch. Her teets were tiny, barely more than nubs, unlike Fluttershy’s own which were squished against her own crotch.

With Twilight's left back leg up on the table, Fluttershy could see the unicorn’s entire undercarriage with ease. This was only made easier by the faint lavender glow that appeared on Twilight's crotch. The light grew brighter by the second until Fluttershy was forced to look away from the other pony entirely.

While her eyes were clearing of spots, Fluttershy smelled something strange, and familiar. It reminded the pegasus of the sweaty, intimate moment she had shared the night earlier with Big Macintosh. The claustrophobic confines of the closet hadn't exactly been romantic, but they stuck firmly in Fluttershy’s mind.

With her head awhirl with thoughts of the farm pony’s cock, Fluttershy opened her eyes to find she was staring at another one. Only this dick was a light purple color and mottled with white spots visible across its hefty length. Comparable to Big Macintosh’s in both length and girth, the futa cock dangled mere inches from Fluttershy’s muzzle.

Its close proximity teased the already aroused mare, though Fluttershy did her best to ignore its presence. It was just a demonstration she told herself, this was all in order to help Twilight become a better teacher. Those thoughts didn't help very much, but they did at least cause the burning sensation in Fluttershy’s loins to ease up slightly.

“I see I have your attention now,” Twilight remarked.

“Oh yeah,” Fluttershy murmured. “I guess so.”

“Good,” Twilight proclaimed, dropping back onto the ground. “Because if you were going to be disruptive again I was going to have to start punishing you.”

“Oh no, that would be just…” Fluttershy shivered. “Terrible.”

“Quite so. You wouldn't want to end up with such disciplinary action on your permanent record would you?” Twilight taunted. “Everyone would know how much of a naughty, naughty mare you are.”

“Y-yes,” Fluttershy stuttered, face beet red and only growing redder.

“Exactly. So let's listen closely while I explain what I just did,” Twilight continued.

While the unicorn launched into another long-winded lecture, Fluttershy looked a bit lower than the board. There, dangling beneath the unicorn’s undercarriage was the thick, completely hard cock Fluttershy had become intimate with a moment earlier. It remained at full mast even while its owner began to ramble about arcane theory and math that Fluttershy had little hope of grasping.

Just looking at the twitching, turgid length turned Fluttershy on, and she imagined it plunging into her ass. Her first instinct was to want it in her other hole, but that was quickly dismissed. Though pleasurable, getting her ass pounded by that thick, meat pole was infinitely better in the pegasus’ mind.

She imagined herself bent over the desk, her pants around her ankles while Twilight pounded her ass. The unicorn’s magically conjured balls slapped against Fluttershy’s pussy while her friend’s hooves grabbed her flanks. The thought caused another wave of natural lubricant to gush forth from Fluttershy’s pussy, further staining her pants.

“Are you even listening?” Twilight asked.

“Uh…” Fluttershy hesitated before shaking her head.

“I thought not,” Twilight muttered. “Well bend over.”

“W-what?” Fluttershy gasped.

“It's time for your punishment,” Twilight stated simply.

Fluttershy reluctantly stood up, and bent over the desk, unconsciously sticking her butt out. Twilight then rounded the other side, and with a swift movement, slapped the other mare’s ass. A second, then a third strike followed shortly after, each one making Fluttershy’s pussy spasm needfully. It was over after the fourth, the entire experience leaving Fluttershy dazed, and yearning for more.

“I hope you learned your lesson,” Twilight stated.

“I’m afraid I haven't,” Fluttershy exclaimed, sitting back down.

Twilight turned around, a shocked expression on her bookish features. “Really now? You didn't learn anything from that?”

“Not a thing,” Fluttershy stated.

“Well then. I guess we’ll have to use more… extreme measures to make sure you concentrate on the lesson,” Twilight exclaimed.

Fluttershy watched as Twilight rounded the desk, and gripped Fluttershy by the flanks. “Now’s your last chance. If you don't apologize and promise to pay attention in class I will be forced to use a slightly unorthodox method to make sure you learn your lesson.”

“Never,” Fluttershy whispered huskily. “I’m a bad student and I need help from my big, strong teacher.”

“Then so be it. But remember, student. You asked for this,” Twilight exclaimed.

Fluttershy was about to ask what exactly Twilight had in mind, only for that question to be answered for her a second later. Twilight's powerful magical aura gripped Fluttershy’s pants and pulled hard in either direction, tearing them down the middle. A simple tug pulled the fabric apart enough to reveal a good chunk of Fluttershy’s damp backside.

The thick ridges of ass flesh created a deep valley in the middle, drawing the eye downward. To where Fluttershy’s pert asshole waited, the orifice tightening upon a breeze of cold air brushing across it. The ensuing shiver that ran up the pegasus’s back was partially due to the cool wind, but mostly due to her own burning desire.

“Now then, focus on the board in front of you, please,” Twilight stated.

Despite everything, Fluttershy looked up, gazing at the blackboard while Twilight shifted behind her.

“Now whatever you do, don't look away from the board,” Twilight continued.

“Yes teacher,” Fluttershy replied.

Twilight began to launch back into her lecture, but Fluttershy didn't pay attention to that. Instead, she focused on the way Twilight's hooves gripped her wide, foal-bearing hips. The tight hold combined with the way Twilight was moving her own hips were all the clues Fluttershy needed to figure out what was going to happen.

And she loved it.

Knowing what was about to happen only turned the pegasus on even more than before. Her arousal built even higher when Twilight dropped her cock between Fluttershy’s enormous ass cheeks. The thick appendage pulsed hungrily in the deep anal valley, burning with an intense, and only barely restrained need.

A need that would soon be fulfilled by having that massive thing plunged as deep as possible into her ass. Before that could happen, however, Twilight pulled her hips back and slid her cock between Fluttershy’s cheeks. Where it vanished, swallowed up by the pegasus’ seemingly endless pillowy backside.

There was a bump a second later, Twilight's cock head brushing against Fluttershy’s asshole. Yet it didn't remain there, and instead shifted lower, descending towards the mare’s pussy. A brief moment of confusion flashed through the fake student’s mind before being washed away by pleasure.

The thick futa cock plunged deep into her marehood, filling and stretching her in a single erotic moment. Then it pulled back, and now slick with Fluttershy’s juices, aligned with the pegasus’ pert asshole. The movement sent electricity coursing up Fluttershy’s spine and, a long, deep moan to spill from her lips.

She shuddered, a moment of ecstatic longing, burning hot in her heart. A sensation that Twilight shared with her, and one which she soon satisfied with a firm thrust of her hips. Her cock, slick with the other mare’s juices, managed to wedge itself into the pegasus’ asshole, prying open the tight orifice.

Both ponies shuddered in pleasure, Twilight's long monologue briefly interrupted by the sound of her pleasure. It didn't take long for the unicorn to gather herself and continue on, pushing herself forward a second time. This thrust was enough to fit the entire head of her cock into Fluttershy’s asshole, the thick appendage popping audibly into the other mare’s needy hole.

Immediately Twilight was assaulted by the incredible sensation of having her new cock squeezed from all sides. Fluttershy’s hooves gripped the desk tightly, her back arching unconsciously to allow her lover better leverage. Which Twilight soon used, the mare slowly, but surely jamming her cock deeper into Fluttershy with long, powerful thrusts.

Each one lasted several seconds and was punctuated by a small twist of her hips, stretching Fluttershy even more. The sensation was incredible and left the pegasus wanting more, though she was unable to fulfill that desire. Contained by the role she had chosen to play, and the tiny plastic chair, Fluttershy could do nothing but take it.

As Twilight droned on and on, she continued her lecture while thrusting into Fluttershy repeatedly. Though not in the least bit romantic, it was weirdly attractive to the young pegasus mare. It was like she really was a student in a classroom, one that was receiving the most erotic punishment imaginable.

Fluttershy could almost imagine the other students surrounding her, casting furtive glances out of the corner of their eyes. Some would view her with disgust, others envy, and a few with complete disregard. Either way, they would all see her there, with a thick futa cock jammed up her ass, getting plowed in front of everyone.

Fluttershy bit her lip and squeezed her eyes shut tightly as an orgasm suddenly shook her entire body. True to her role, Twilight didn't slow down or even acknowledge what was happening to the other pony. She just kept on thrusting, kept on stuffing more of her cock into her friend, until at last, their hips met with a wet squelch.

The feeling of fullness was incredible, the mind-blowing sensation ratcheting up her pleasure to eleven. Fluttershy wanted more, she wanted to be stuffed and fucked like the butt slut she knew herself to be. And Twilight did just that, the unicorn maintaining her lecture even while she began to pound Fluttershy’s ass.

Over and over she drilled forward, yanking her cock a few inches back before shoving herself back inside. Her movements were inelegant, and not expertly done, the unicorn clearly unused to having a dick. It didn't matter though, the entire situation was just so arousing, so captivating that it more than made up for the slight awkwardness.

Already Fluttershy could feel herself growing close to a second orgasm, one that may even eclipse the first. Twilight wasn't too far away either, the mare’s thrusts growing with speed and losing what little sense of order they previously had. Sloppy, fast, and hard, her wonky rhythm was still incredibly pleasurable but had thrown off her lecture.

“F-fuck,” Twilight muttered. “It's coming. I can feel it building.”

“Me too, I’m close,” Fluttershy whispered.

“Are you ready for your final punishment, you naughty, naughty mare?” Twilight asked in her best authoritative tone.

“Y-yes! Give it to me!” Fluttershy cried.

“Let's see how enthusiastic you are with a belly full of my cum!” Twilight declared.

The unicorn’s hooves gripped Fluttershy’s hips even tighter, digging into her soft, supple ass cheeks. Forced forward by the sudden pounding crescendo of Twilight's thrusts, Fluttershy grabbed hold of the desk and held on for dear life. She did this just as all sense of rhythm or even a thin veneer of planning vanished, replaced by raw, naked lust.

Twilight grunted as she all but threw herself forward, jamming every last inch of dick into Fluttershy with every thrust. The pegasus could barely keep herself from cumming but she held on, resisting the siren song of ecstasy. Until at long last she as well as her partner, could no longer resist the call, orgasming in near-perfect unity.

One last thrust pushed the entirety of Twilight's cock into the tight confines of Fluttershy’s vice-like ass. The first surge of jizz into her body sent Fluttershy over the edge, her pussy quivering and erupting with a wave of girl cum. Her pants only became wetter as time passed and she continued to spasm in ecstasy.

Which reached even greater heights when Twilight leaned down and bit her neck, forcing Fluttershy’s face into the desk. The rough, yet not painful treatment left Fluttershy feeling used in all the ways she less than secretly enjoyed. For a moment Fluttershy thought she saw stars and worried she may be about to pass out, but then it passed.

Her orgasm continued, as did Twilight's but it was beginning to taper off after what felt like a short eternity. It was then, and only then that Fluttershy noticed just how full she had gotten, her stomach swelling ever so slightly. It wasn't an inequine amount, but it was enough to leave Fluttershy feeling like she had just had a rather large meal.

And she loved it, a hoof caressing her belly while a ragged moan spilled from her throat. A feeling she shared with Twilight, who had collapsed atop the other mare, the unicorn’s body going limp. For nearly a minute they remained there before at last Twilight was able to lift herself up once more.

“That was… amazing,” Twilight muttered.

“That was quite possibly the best sex I’ve ever had in my entire life,” Fluttershy admitted.

“S-same,” Twilight awkwardly agreed.

“But um, maybe you should pull out of me. The kids should be coming for their lesson soon and I don't want them to find me like this,” Fluttershy whispered.

“Oh uh, right,” Twilight murmured.

Twilight stood back up and began to slowly pull herself from Fluttershy’s cloying depths. A bit reluctant to pull out at all, Twilight took her time, that was until she heard the door to the library open. The loud squeaky hinges heralding the arrival of nearly a dozen foals who excitedly sprinted inside.

With a confused squawk of surprise, Twilight awkwardly fell backward, her magical cock emerging from Fluttershy’s hole. Without any footing or anything to hold onto, Twilight tumbled gracelessly, landing on her back. There she lay, dazed and confused while a jet of her cum shot from Fluttershy’s hole.

The shot of jizz spurted out across the floor, the flow quickly slowing to little more than a trickle. Which only further stained the already thoroughly ruined pair of pants Fluttershy still wore. Now shuddering, and laying half draped over the desk, Fluttershy squeaked as another eruption of cum shot from her slightly gaping hole.

Twilight reacted first, dismissing her cock with a brief flash of magic before hopping up.

“I’ll go distract them. You get presentable and clean this place up. The bathroom’s over there,” Twilight ordered.

Fluttershy blearily followed Twilight's hoof to the corner of the room where a door rested. She could barely nod her head before the unicorn was already on the move, sprinting up the stairs. As Twilight moved, she cast a quick cleaning spell on herself, removing the majority of the evidence of their love making.

“W-wait,” Fluttershy called.

Twilight paused mid-stride. “What is it? Did I get some on me?”

“No. I just erm… wanted a kiss,” Fluttershy murmured.

Twilight smiled, and with a flash, appeared before the pegasus. She then planted a brief, but passionate peck on Fluttershy’s lips before disappearing once more. Now atop the stairs, Twilight flashed her friend a smile before continuing to sprint up the steps two at a time.

Left alone, and utterly spent, Fluttershy wanted to panic, but couldn't help but smile. Despite everything, she had enjoyed every last second of their passionate encounter. Only a small, nagging thought stopped her from grinning like a mad pony.

First Big Macintosh, now Twilight. I wonder if anyone else is interested in me like that?

Author's Note

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