Do-Me Decimal System (or 'Twilight's Special Project')

by darf

Rating: mature
Tags: Romance, Anon, Porn, Trixie, Fetish, Sex, Twilight Sparkle, Profanity, My Little Pony: Friendship is Magic, Human
Length: 8457

Twilight needs your help with a special project: taming her new pet Trixie. Only Anonymous' strong, human hands will do for pony-sex punishment...

Mommy-Domme-Sexy-Librarian!Twilight enlists Anon/Leo's help in subjugating an over-teased and helpless Trixie in a shed on the outskirts of Ponyville. After proper assistant/sub-slut introductions, Twilight busts out a new invention—the My Little Cockring™, capable of helping anyone hold off from properly busting a nut until their Mistress Mare says so!

A commission for Anonymous.

Content Warning: BDSM with emphasis on D/s, human x pony, orgasm denial, general naughtiness

If you enjoy our writing, you can support us on Patreon. You can also commission us for horsewords by sending a PM on Fimfiction, or anywhere else we're located.

Big thanks to our current patrons for helping make this story and many others like it possible: Sorden, carcinoGenetecist, Jake, infernap42, and Nick. <3

Published 2020-07-08 01:10:03 UTC
Last updated 2020-07-08 01:10:03 UTC

for some reason we always have a hard time thinking of really good-sounding horse puns

"I really appreciate you taking time during the weekend to help out around the library," Twilight says. Her nose is buried in the cumulative literature of her roving book-cart, which is piled as high three ponies standing atop each other, and yet somehow manages not to wobble precariously at all. Twilight's face is book-planted, but her backside is freely exposed, waggling idly back and forth underneath her provocatively-short librarian's skirt—the one she'd taken to wearing since you started working here about two months ago.

Oh, right. You. Well, that is to say...

Let's just get the whole thing out of the way with. Hapless fan of the show wakes up one day in his vision of Equestria, suddenly everypony is best friends and begging you to babysit... you know the drill.

The ponies call you 'Leo'. On account of 'Anonymous' gets annoying real fast.

"It's no problem," you say, stashing a book arbitrarily in the back of Twilight's cart while standing at the perfect angle to stare at her butt unobstructed. "I didn't really have anything planned anyway. Just sitting around staring at pictures of pony—I mean, going over the first draft of my memoirs, before submitting it for publication."

"Ooh, memoirs?" Twilight's voice comes out with a slight echo, muffled as her head is by the surrounding books, but her voice sounds as flirty and bouncy as ever, even when discussing fictional autobiographical writing projects. "That sounds interesting. You'd be the first human in Equestria to publish their own personal experience. Meeting ponies, getting to know them... it's 'stranger-in-a-strange-land' come to life! Sounds perfect."

Somehow, all of Twilight's verbal enthusiasm feels less impactful than the way she wiggles her butt side-to-side with a little extra oomph... when she was happy, it was easy to tell. Hard to ignore. Hard not to notice. Hard...

Ahem.

"Can you pass me that catalogue of Pre-Celestial literature? I'm going to be heading to the archives next, and it's been out of place for at least a week."

You're tempted to just grab a random book and hand it over, giving yourself a few extra seconds to stare before Twilight notices she's been given the incorrect volume... but the big, dusty book is right there, a stroke of good luck, since you're still working on memorizing the weirdly-arcane feeling organization system Twilight's been trying to teach you for the last two months.

"Here," you say, and hand her the book.

Twilight pokes her head out of the book tower to smile at you, grab the book, and then dive back in. Her butt remains firmly attached to the back of her, protruding and perfectly positioned for staring. So you stare.

And stare.

And stare.

Twilight's voice drifts into your ears like a thick syrup accidentally laced with words.

You nod, eyes still locked on her squishy purple butt.

Then her face appears, eyebrow raised, head tilted.

"So you think you'll be able to help? It's just a pet project, really, not anything I can't take care of by myself..."

"Oh, sure," you say, nodding again. Twilight smiles, looking happy that you've agreed to help out. Getting along with ponies is so easy; why doesn't anyone just agree endlessly to whatever they say while not really paying any attention to... to...

"Wait," you say. "What am I agreeing to help with again?"

"I just told you," Twilight says, her voice slightly huffy. "Somepony who passed recently has just donated their estate's entire private collection to the library. I need your help to, uh... reach the really high shelves."

Makes sense. Ponies aren't particularly known for their tallness, and without a pegasus or a ladder, getting those high-up books can be a real...

"Wait," you say again. "Why don't you just use your magic to get the books on the tall shelves?"

"I can't be using my magic all day for just anything," Twilight said with an eye-roll and a sigh. "What if somepony decides to challenge the very nature of friendship again, and I've spent up all my spellpower levitating books around?"

"You make a fair point," you say. "I guess I could help then. I already agreed to sort books with you most of the day anyway."

"Great!" Twilight springs out from the book-cart with a velocity more Pinkie's style, but decelerates quickly enough to not cause any literature-related disasters. Her face is practically glowing, and for a moment you feel a little swelling in your chest that competes with the swelling somewhere else for 'best feeling of the last five minutes'.

"The estate's on the outskirts of town, but we should make it there in an hour or so if we leave now," Twilight says. Her horn glows, and books begin to fly around the room, as well as quills, an ink-well, and several pre-packaged sandwiches she'd evidently stashed away for lunch.

You raise an eyebrow of your own. Raising someone else's eyebrow would be weird.

"Didn't you just say something about not wanting to waste your spellpower on books?"

Twilight gives you a sideways glare as she continues packing.

"This is different," she insists. "In this instance, I'm moving the books with magic because I want to. For my special project, I'm going to get you to move the books, because I, don't want to."

Twilight grins mischievously at you. Under her glasses, in her cute little skirt, she almost looks like a boarding school headmistress, complete with sultry stare and... well, there's a lot you can use as a makeshift whipping implement, in a pinch.

"Come on," Twilight says. She grabs you by the hand, her hoof warm and soft as the rest of her, and yanks you towards the library door. "I've been waiting to do this for weeks."

"Has anyone ever told you that you get a little too excited about books sometimes?"

"Only everypony I've ever known."

"Fair."

The two of you are out the door, with Twilight in the lead. It's a good thing she knows where you're going... not because you're worried about getting lost. Just so you can walk behind her and stare at her but the entire time.

Which you do.

"You know, I didn't even know there were any houses this far away from Ponyville proper."

Twilight's expedition has led the two of you through dilapidated homesteads and rolling hills, far enough away from the town that it disappears on the horizon if you blink the right way.

And here in the middle of nowhere, somehow there's a piddly-looking shack managing to stay upright. It barely looks big enough for two ponies, let alone a lifetime of collected literature... that shack looks barely big enough to hold the dust. And Twilight hates dust.

"Come on," Twilight says, ignoring your observation completely. She peers through a small slit carved in the front of the door and giggles to herself before unlocking it. "This'll be great. You're the perfect candidate for this project."

"I don't see what's so special about sorting a bunch of old books," you say as you begin to walk inside the shack. "Is this one of those 'bigger-on-the-inside' situations, where all the walls tower up with a bunch of holy shit that pony is tied up and naked."

"Ponies are usually naked," Twilight corrects as she slides in behind and around you, then shuts and locks the door. "But yes, she is tied up. And gagged. You could have said gagged."

In the center of the shack, lounging—is that right to say, being tied up almost like you're in a medieval torture rack?—well, splayed out, then, but in a leisurely sort of way, with pillows to rest her head and butt on—her blue butt, that is to say—is the Great, but at the moment not entirely so powerful, Trixie. Moaning, panting, writhing, sweating and dripping filly-juice down both legs and leaving a puddle on the floor. Her eyes are wild, and her head snaps in your direction as she hears your footsteps on the wooden floor. There's a black blindfold tied over her eyes—she can hear you, and smell you, but that's about it. Unless you count 'feeling your body heat change the tension of the air'. Which you do. You can feel her wriggling and begging from here.

Twilight giggles behind your back.

"She's in quite a state, isn't she?"

You're uncertain whether or not to stare. Your fragmented willpower elects to take in healthy doses of the horny, helpless pony writhing around next to you, since it's not evidently the case that she's able to notice you doing so.

Through her gag, Trixie lets out a long string of mumbles that contains something sounding ever-so-slightly like 'help me'.

"Does this... have anything to do with that book collection?"

Twilight giggles again. She's fussing about the shack, picking up things like a thin-tailed flogger, a black plastic plug about four inches long, and a whip ripped directly from the talons of a demon in Tartarus. The ends looked pointy.

"Are all humans this slow, or is it your special talent?" Twilight's changing her clothes too, keeping the skirt, but she's putting her mane up into a bun, and those glasses look suddenly more authorial than ever... add the black fishnet top and we have a profile to remember.

Belatedly, you shake your head. It takes some time to process questions through muffled pony-sounds and Twilight's butt flashing in your direction every other minute.

"So it's not about a book collection?"

"No, silly." Twilight pats you on the head, then, uncharacteristically hard, slaps your tush enough to make you jump a little.

Your eyes fall instantly to the flogger in her other hoof. Where's she going to be pointing that thing?

"Time for introductions," Twilight says. Her voice takes on a stern and commanding tone, a stark shift from her normally soft and playful banter in the library. Somehow, even just standing there, she seems taller. More in command. "Leo, have you met Trixie?"

You look down at the blue mess locked in the set of stocks at the room's center. As though she can feel the weight of your eyes on her body, Trixie moans and bucks her hips as far up as she can manage, which is only a few inches off the pillow cushioning her soft, blue butt.

"Uh... I think we've run into each other once or twice. She's kind of a... force to be reckoned with in Equestria, if you know what we mean."

"Oh," Twilight says, smirking gleefuly, "I know exactly what you mean."

Twilight rests her hoof gently on Trixie's chest, and the poor blue pony writhes again, her body shuddering like she's been sizzled by an electric charge. Twilight smiles as she traces her hoof along Trixie's chest and stomach, teasing with little jolts down between her legs, but never far enough to touch anywhere that might provide relief.

From the look of things, Trixie's been here for a while. Struggling. Waiting. Winking, and leaking onto the floor.

"Trixie," Twilight says, her tongue lapping playfully at Trixie's ear, "I have someone here for you. Someone who's going to help us with our... experiment."

Trixie shudders as Twilight draws out the word.

"Does that sound like fun, Trixie?"

"Mhnm, mhns hmmnmnnn!"

That sounded like a 'Yes, Miss Twilight' through about two inches of solid plastic. Poor thing.

Twilight turns back to you, her hoof still on Trixie's stomach, moving in little circles.

"Trixie and I have a little arrangement," Twilight says. "She does what I say, and if she's good, she gets a reward... usually a chance to cum. She's sooo needy, always wants somepony to be playing with her pussy..."

Trixie wriggled and jerked her hips upwards as Twilight traced her hoof lower, hinting and teasing just above Trixie's clit, even dashing over it once to the sound of Trixie squealing into her gag.

"Anyway," Twilight went on, "it occurred to me after working with you in the library for so long, you'd be a perfect fit for the new toy I've been working on. And who better to participate in the other half of the experiment than my dear, diligent student, the Simpering, Slutty Trixie? Hmm?"

Your eyes move back and forth from mommy-domme Twilight to temporary-sex-toy Trixie. A purple posterior you've been eyeing for the last two months, and an oversexed sub-slut begging for attention with every fiber of her being. She might break the restraints if Twilight goes on like this.

"I'll do it," you blurt out. "Whatever it is, I'll do it. For science, I mean."

Twilight's eyes light up, and her smile grows even more devilish, if that's somehow possible. Instantly, her horn glows, and a small, black velvet bag floats over from an unlit corner of the room. It's a miracle there's enough sunlight through the windows to see at all.

With a hungry grin, Twilight undoes the string fastening the top of the bag, and unveils the toy she's been waiting to try out.

"That looks like a plastic Cheerio™," you say. "But fancy colors."

"It's a cock ring," Twilight says matter-of-factly, completely ignoring your attempt at humour. "If you've never seen one before, I guess it's a little unusual looking... but there's really not much to it." Twilight holds the tye-dye rubber circle in your direction. "You put it around your cock, and it goes tight and keeps you from cumming... without my permission, that is."

You give the ring an experimental stretch. Seems flexible. And... sparkly?

It dawns on you slowly, as most things do, surrounded by pony-sex smell and muffled whimpering.

"You want me to wear this?" A brief pause, where Twilight nods at you, smiling. "Now?"

"That was more or less the idea," Twilight says, a hint of playfulness creeping back in to her voice.

Staring down at the cock-ring, you notice a tiny scribbled name carved delicately into the plastic.

"'My Little Cockring™?'" you ask flatly.

Twilight giggles and nods.

"Yep. Cute, isn't it?"

"This is all coming on a bit fast," you say. "Not that I'm objecting to participating. I just feel like it would be a good time to ask some questions before, uh, volunteering myself for a 'special project' I don't fully understand."

"Ask away," Twilight says. Her hoof has finally found its way properly between Trixie's legs, and she's stroking and teasing the poor blue pony much the same way you might tempt a dog by holding a bone-biscuit over its head. The difference here was a matter of hours—if a pupper could keep a bone on its nose for just a minute, it was a very good boy or girl or nonbinary pup-like entity. But Trixie had been struggling against orgasm for who knows how long, and the signs of wear were obvious. Nopony who wasn't aching for an orgasm looked that disheveled and desperate. You can practically make out the movements of her mouth behind the ball gag, 'help me's and 'let me cum's muffled by blue plastic. To match Trixie's coat, of course.

"Firstly," you say, "is this all consensual? Trixie's not here against her will or anything like that?"

"I can guarantee you she's very willing, but would you believe me in this position anyway?" Twilight's smile is studied and sultry, it's hard to remember all the time how smart she is, until she drops a load of contextual knowledge like that. Her hoof keeps going, up and down Trixie's slit, little swirls around her clit that make Trixie's whole body jerk and her hooves thrash against the boards and clasps restraining her.

You could always get Twilight to remove the gag to hear consent 'straight from the horse's mouth', so to speak... but then again, as Twilight points out, how sure can you be of anyone's willingness in a scenario like this? Trixie could be under strict orders to simply agree with everything Twilight says, and that'd be no closer to 'absolutely informed consent' than before asking. But somehow, you have to move forward.

"I was thinking about asking you to take the gag out so I can hear Trixie consent for herself," you say, wondering at what point it's appropriate to begin removing your clothes, "but it occurred to me—"

"—how can you be sure of anypony's willingness in a scenario like this? That Trixie could be under strict orders to simply agree with everything I say?"

Twilight grins broadly, like a bully puncturing somepony's balloon.

"Yeah," you say, scrunching your mouth up slightly. "Something like that."

"You're in a bit of a catch-twenty-two, as it seems to me," Twilight says. "Maybe you should just get on with the rest of your questions." Twilight leans down until her mouth is next to Trixie's chest, then extends her tongue and licks in a long, delicate line from one end to the other. Again, Trixie seems to beg for help through her ball gag and restraints.

"What exactly is it you need my help with here, anyway? It seems like you've got the situation more or less, er, 'under control'..."

"True," Twilight says, sticking out her tongue and giving Trixie's stomach another lick before she turns her head towards you. "But there's a special magic when humans and ponies come together. Trixie's just the same as any slutty filly, can't wait to get her hooves on that big human dick... watch. If I keep talking about it now, it'll practically push her over the edge." Twilight leans close to Trixie's ear and nibbles on it a little. "Human dick," she says, far louder than a whisper, and Trixie groans and arches her hips up, practically throwing her pussy at you from her place on the rack.

Twilight giggles and gives Trixie one last nibble before moving away from the poor, tied up pony.

"See?" she says. "She's a total sucker. Speaking of which..."

"Is this the part where you tell me what I'm supposed to be doing?" you ask. As Twilight bustles about the room, you can't help but stare at her ass again, the one part of her that seems bouncy and and inviting no matter how stern the rest of her is acting. Bouncy, bouncy, bouncy, purple pony butt. It's a wonder you ever got any work done at the library at all.

"Hang on," Twilight says, her voice semi-distant as she roots through one of her bags, "I've got some lube that'll make things just right... it's hot and cold, really gets her going." Twilight hovers the bottle over to you with a lavender glow.

It's cool and firm in your hand, and the top uncaps easily, with a little glob of the sticky gel poking out of the applicator.

"Just rub some wherever you feel is best," Twilight says, smiling her languid smile. Still, her glasses seem less 'innocent school-filly' and more 'demanding headmistress'. You feel a nervous lump in your throat disappear as you swallow.

"Like... here?" You extend a hand, your fingers hovering just inches away from Trixie's dripping pussy. You can feel the heat of her body radiating off like a fresh-lit fireplace. So warm you can practically clench your first and squeeze her through the tension moving in both directions.

Twilight nods, still smiling.

"Uh-huh. Get her all nice and slippery."

"I dunno if she needs to be any more slippery than she is, to be honest—"

Twilight grabs your hand and forces it down onto Trixie's warm, twitching cunt, and she moans and thrashes up into your touch like she's been possessed by a sudden and intense specter, intent only on keeping her leaking slit in contact with your palm.

Twilight's grin grows even wider as she watches you begin to rub your palm up and down Trixie's slit.

"That's it," she says, her voice stern, but soothing. "Trixie loves it when humans play with her cute little pony pussy." Twilight leans over to her poor pet and gives strokes Trixie's cheek softly with her hoof. "Isn't that right, Trixie?"

"Mhmmphmmn!" is, once again, the best available translation.

"Maybe we should take that off so Leo can hear your desperate little begging voice for himself," Twilight says. Her horn glows, and as simple as that, the clasp at the back of the gag unfastens and the whole thing pops out of Trixie's mouth, like a toddler who's swallowed a bouncy-ball. Like the toddler, Trixie can't help from coughing, even though the plastic's been lodged in her mouth, instead of her throat.

It takes a few seconds for her to catch her breath. Even then, she's incoherent for a bit, mumbling and sticking her tongue out between her lips like she's forgotten how to form sentences after being tied up for so long. Like the world has ended while she was in here, struggling to cum and also not to cum.

Twilight follows by removing the blindfold. It's a bit longer then, maybe a minute or two, before, after a long gasp, Trixie finally lifts her head, opens her eyes to the bare minimum of that definition, and gives you her best 'I'm-okay-and-absolutely-consenting-to-this' smile. It looks wearied, damaged, and a little uncertain. You're familiar, having practiced the look yourself before. It's very hard to look convincingly happy when you're being tortured, even if the torture is the type that happens to be your favorite. A special subtlety is required for the reading of emotions in this context.

"Trixie," you say, pausing the movement of your hand and resting two fingers just on the entrance to Trixie's slit, causing her to moan and buck her hips upwards against your hand. "Is this all okay? You're not here against your will or anything like that?"

Trixie shakes her head back and forth desperately, conveying through force, rather than delicacy, how intently she is not here against her will. Willful. She's managing most of it to keep from cumming, still.

"And when Twilight says you like being tied up and tortured to the brink of orgasm over and over... that's true too?"

Trixie shares a look with Twilight—a sad, sappy dog looking for permission from its owner. Twilight nods, and Trixie turns her gaze back to you.

"Yes," Trixie says. Her voice is shaky, evidently out of practice even in the few hours that her mouth was otherwise occupied. "The Great—that is, the, er, Simpering... S-slutty Trixie..."

Twilight nods and gives Trixie a pat on the head, which is answered with a cute little mewling noise.

"The Simpering and Slutty Trixie," Trixie begins again, "is very used to being teased. It is our job to make Mistress Twilight happy, which often means letting her tease and, t-torture us until we're, q-quivering messes of, of filly-juices and, and our whole body is aching, begging for that final push over the edge of the cliff..."

Trixie shudders as Twilight runs a hoof down her chest, resting it just above her clit and pressing down to make the helpless blue pony whimper again, even louder.

"That's right," Twilight says, her tone smug and satisfied. "Trixie loves being tied up and teased like a little slut... and that's what you're here for." She turns her head to you, the devil's smile on her face. "You're going to help me tease Trixie until she turns into a blubbering, sex-crazed mess."

You raise an eyebrow at Twilight.

"Oh, alright," she says. "Even more of a blubbering, sex-crazed mess."

You nod. That sounds a bit more accurate.

It's a tad odd, having Trixie's writhing body in the periphery of your vision as you're discussing sexual logistics with Twilight... you can't imagine how Trixie feels, being hung up and toyed with like a perpetual plaything. If she has any objections, she's certainly not sharing them.

"I want you to tease her as much as possible... with your hands, your fingers, your mouth... your cock, as long as you're wearing your new present." Twilight smirks and gestures to the cock-ring, which has been waiting in your other hand this entire time. The more you squeeze the material between your fingers, the more yielding it seems, until you can almost imagine yourself wearing it comfortably while rutting the tied up Trixie like a rented prostitute.

"You mean I'm allowed to... fuck her?"

Twilight shakes her head.

"Yes and no. The two of you are playing as pets today... and that means you don't get off until Mistress Twilight says so." That smirk again, that says 'test me and see where it gets you'. You've never been a fan of being whacked on the backside with a ruler. Trixie, on the other hand...

"I don't get to cum?" you ask.

Twilight shakes her head.

"You do," she says, "but my little present will make sure you save up your load for when it counts. I get to say when you shoot it—and Trixie's gonna be the one who gets sticky."

"Does Trixie get to cum?" you ask.

Twilight gives you a look™.

"What do you think?" she asks.

"Point well taken," you say. "Just asking that kinda makes you sound like a mistress already—er, Mistress Twilight."

"Just 'Miss Twilight' is fine," she says to you, giving you a small kiss on your forehead and giggling. "Only she has to use the full title. And she knows why. Isn't that right, Trixie?"

"Yes, Mistress Twilight!" Trixie yelps her answer back at such a high frequency it sounds like she's been shot. Probably a conditioned response to many months' worth of belt-whippings.

"You remember you're not to cum, no matter how good Leo's attention feels. Understood?" Twilight runs her hoof along Trixie's cunt and presses down hard on her clit, making Trixie gasp and arch her back until her butt's floating off her pillow again.

"Yes, Mistress Twilight!" Trixie says again. It sounds like she's barely managing to put the words together through the haze in her head demanding attention between her legs. All this just for offering to help Twilight out around the library—what delightful karmic allocation.

It's hard not to just stand and stare at Trixie's damp, writhing body, but Twilight's staring at you, and at your hands, and so you can't help but move your palm until your fingers are just above the outline of Trixie's two slightly-swollen pussy lips. She groans when your fingers move closer to touch them, and the slippery feeling as your fingers slide between makes you wonder exactly how much sex-juice a mare can produce. Trixie's looks to have been like this for at least an hour, and she's still dripping on the floor like a leaky faucet.

You can't help it. One of your fingers slides in so easily, it's like parting water. Trixie inhales sharply, then moans loudly with all of her stored breath, adding in cute little squeaking noises as she feels your second finger plunge inside and the two digits begin to push and arch up inside her pussy.

The way her entire body arches to your touch is intoxicating. It's an overwhelming output to such a diminutive input, just barely teasing her with both fingers, and yet she's howling like you've already started ramming her with your cock ring in place. Speaking of which...

"Let's get that on before you go any further." Twilight—you've already started referring to her as 'Miss Twilight' in your head—levitates the multicoloured rubber-feeling ring out of your hand and guides it to the head of your cock. She must have noticed you were getting hard. You're not sure through what mechanism unicorn magic operates exactly, but it still feels a bit like a hand holding your dick straight as she slides the ring down.

You stifle a gasp. The plastic isn't cool or particularly unusual. It just makes your cock feel that much more stiff, like you've got a little something extra in store for the mare you're going to be shoving it in. The sensation of having your erection coaxed even further to life is enough to distract you from Trixie for a moment, but her desperate moaning brings you back, almost forgetting part of your hand was even inside her. Then you start moving, slowly as consciousness redirects, and then faster and more forceful once you've slid back into your body properly. You can really focus on the face Trixie's making as she tries not to cum—a mix between 'agonizing pain' and 'overwhelming bliss', somehow mixed up in the contortions of her mouth and her intermittent moans and squeals.

Before you can get too focused on paying attention to Trixie exclusively, Miss Twilight—that's fine, for now—hops up onto Trixie's chest and positions herself with her legs spread more or less directly in front of your face. Trixie whimpers slightly at the extra pressure, but she's cushioned, and Twilight—er, Miss Twilight—doesn't weigh that much anyway. Maybe her butt. But not much else.

Twilight's orders are implicit, with her legs spread, her pussy doing the same, one hoof on either side and a lick of her lips in your direction. But even then, maybe still you're not sure. So she gives you a reassuring smile, and nods towards her wide-open slit.

"Go ahead," she says, somehow able to dredge up a tone that's both reassuring and commanding at the same time. "I want you to lick my pussy. It's all yours."

You're acutely aware of your two digits still inside of Trixie, who's wriggling and writhing, searching for more penetration to the best of her abilities, and maybe coming away with a half inch each time her body jerked back and forth. Then there's the ring, tightening still around the base of your cock, you're not sure you remember the last time you felt this hard, you can feel your balls tingling with a fat load of stored up cum.

You clear your throat and look to Twilight again for instructions.

"Do you want me to, uh—"

"Fuck her?" Twilight grins and runs a hoof slowly along Trixie's cheek, making her pout and whimper. "Yes. The sooner the better. But neither of you are to cum until your Mistress does first. Understood?"

You and Trixie nod almost simultaneously. Trixie is a bit behind, like her every action is being translated through a fog of her all-encompassing desire. It's a struggle not to just dive in and try to get the poor thing off right away.

But Miss Twilight's in charge right now. And for good reason.

You manage a nod of confirmation, then slide your fingers slowly out of Trixie's soaking-wet cunt. As she's been doing perpetually, she shudders and moans as anything touches her, but you can hear her whimpering to be full again, to have her pussy played with even if she know she's not allowed to get carried away. The tortured look on her face amplifies as she stares at you between her legs, lining your ring-harded cock up with her dripping slit. The second the head of your prick touches against her slick skin, she screams, and is muffled instantly with one of Twilight's hooves. You slide the tip of your cock up and down her lips a few times, drinking in the way she arches her back and moans deeply in proportion to your touching.

"You can see why I had her gagged," Miss Twilight says, smirking, with a hoof still in Trixie's mouth to muffle her.

You nod back. It's hard to talk and be a sex puppet at the same time. You find yourself focusing on one or the other.

There's Trixie's smooth cunt, sliding around your cock, her whole body seizing as you plunge your shaft inside her...

And there's Twilight pushing her hips even further forward, practically forcing her clit into your mouth, kind of just grinding her pussy all over your face until it's soaked by adjacency, and then centering in on your mouth so you have no choice but to part your lips and start licking. Twilight lets out a low, throaty groan, shuts her eyes, and grabs the back of your head with booth hooves to hold you in place and force your tongue to press even harder into her clit.

Trixie is howling into Twilight's hoof, a miracle she's managing to hold it there, that any part of this three piece sex-puzzle isn't miraculously compromised to let the whole thing tumble down. Somehow, everyone involved is managing to make it work. Even Trixie, who's been teetering on the edge of explosion for over an hour now. That's certainly one type of 'Great and Powerful'.

The look on her face, though, as you manage to pull your hips back, and the two of you feel the friction of her velvet-soft cunt as you slide out, inch by inch... it's the worst you've seen her, like she can't bear it, she looks likely to yank Twilight's hoof out of her mouth and beg with every word in her vocabulary, staring with—

"Fuck me!" Trixie begs, fulfilling prophecy by yanking her head sideways and spitting out Twilight's hoof like a sour jawbreaker. "Please, I can't take it anymore, I need you to—"

Twilight gives the Slutty and Sex-Crazed Trixie a gentle slap to the face—not to enough to really hurt, or do any real damage, but to remind her exactly what kind of behaviour's required of her around her Mistress.

It seems like the slap might have the opposite of the intended effect—Trixie holds a hoof to her cheek and pants like a dog in heat, seemingly in love with the tingle of pain instead of corrected by it. But this is a cycle Twilight's seen before, and she knows that if Trixie wants any more play at all, she'll reign in her natural slutty impulses and behave like a good girl for the rest of their 'special project'. What would Leo think if she was to go on like such a naughty filly? For shame.

It's not easy to know how to react to somepony you're fucking being slapped in the face. Maybe all you can do is take it in stride. Nopony seems not to have enjoyed it, in any case.

"I'm sorry, Mistress Twilight," Trixie says after a tantalizingly elongated silence. "I spoke out of turn. You shall be the one to tell me when to be fucked, and, and he—"

"He's the one doing the fucking, so be a good girl and don't beg so desperately," Twilight finishes. She gives Trixie a pat on the head, and Trixie looks up and bats her eyes and smiles, like she really is a good girl.

Twilight gives you a smile, then a nod.

"Continue," she says. "But do it at your own pace."

"Understood," you say. "Er... Miss Twilight."

Miss Twilight smiles even brighter at your extra effort.

That effort, evidently being expended also in concentrating the brunt of your willpower not to A) fuck Trixie's brains out at peak velocity, or B) tease yourself tantalizingly with just the tip of your cock slipping inside her, until you're ready to bust a nut all over the inside of that pretty pink-on-the-inside-blue-on-the-outside pony-puss.

Only... Twilight said her special ring would keep you from busting a nut until she said so. She said you could cum while wearing it, but that all that sticky jizz would be saved up until she gave you permission to let it out. And she'd also said... no one comes before Mistress Twilight? It's getting hard to remember, your cock in one pony, your tongue in another. Keeping two separate motions alone is a bit like rubbing your head and patting your stomach. More difficult, because Twilight's clit seems particular, the way she likes it rubbed just so. Less difficult, because no matter how you touch Trixie, she explodes like a kinked firehose every time. Maybe just... different, because it's all through the haze of an urge somewhere inside you to give in to the natural feeling that always comes with sex. Holding control over it, or, more accurately, Twilight holding control over it, makes you feel owned and possessed in a way you're not sure you're familiar with, or comfortable with, or even certain about. But it's one thing to question, and another to stop yourself mid-thrust into Trixie's pussy, or your tongue from spiraling around Twilight's clit as she gushes girl-cum all over your face.

"You're doing a good job so far," Twilight says. She's running her hooves through your hair between forcing your head forward into her cunt, and the end result is that strange mix of nurturing command again—Twilight has a hold of you, and she knows exactly what to do with it. And you're not afraid, because you can trust that certainty, believe in it, and her.

"Now it's time for Trixie to attend to her Mistress personally," Twilight says between moans, finally removing her cunt from its fixture on your mouth. "Your Mistress is getting close. Be a good girl and make me cum and I'll let you get off as soon as I'm finished."

Trixie lets out a panicked-sounding moan, it's hard to translate exactly, like she knows she's already at the edge and isn't sure she can take even one more nudge, but if she tries, and she manages to do it, she'll finally, finally be able to cum again—and, what's more, she'll be a good girl, and that's a feeling you can't put a price on.

The shift looks effortless for Twilight. Her smile remains, devilish and knowing, as she lowers her snatch into Trixie's waiting mouth and savours the panicked, desperate licks of a captured slut in borderline-heat. Twilight moans loud and runs a hoof through Trixie's frazzled, dampened mane. Even muffled by Twilight's cunt, you can hear Trixie teetering on the edge of her willpower. The dam is beginning to fall apart piece by piece, and only allegiance to Mistress Twilight remains to keep the water at bay.

For your part, it's nice to just be able to focus on your dick inside Trixie again. But as soon as you've started to slow your thrusts and make them more purposeful, Trixie clenches and squeezes tight like she's trying to prevent you from moving any further, either shuddering on the very precipice of her climax, or needing you to remain absolutely still while she attends Twilight's pussy, to get her Mistress off before she cums herself, the 'bad girl' label hanging treacherously overhead. Please, you can feel her saying through her whines and the slurping of her tongue, please, Mistress, I can't take it any longer.

Twilight's eyes flare open, then shut tightly. "Harder," she says, putting both hooves behind her own head and rocking her hips forward. "Don't you dare stop."

Trixie doesn't need to be told, a barreling freight train couldn't dislodge her lips from Twilight's, and after a few tense seconds where Twilight's body seizes like a bough of wood about to be broken by the storm, you feel it, and Trixie feels it, and Twilight lets out a furious, triumphant groan as her legs shudder and her pussy quivers and a small trickle of filly-juice leaks into Trixie's lips, which she laps up like it's flavoured water.

Twilight doesn't say anything else as she cums—just grunts, riding her orgasm down a gentle slope, still completely unconcerned for the two pent up partners waiting on her to finish. She's done when she's good and ready to be done... and even then, she gets off Trixie slowly, leisurely, making sure not to appear rushed or even a little bit out of place. Her face is only slightly flushed from her orgasm, and she lets out a little sigh as she steadies herself beside Trixie's restraints, but that's it.

"Good job," Twilight says, slightly breathless, but still composed. She adjusts her glasses and ruffles her skirt a little, which doesn't do much to dull the appearance of an off-duty librarian who's just gotten her snatch eaten out... but it's a nice gesture, and it does make her seem a little more together.

At some point, you forgot your cock was still attached, as if noticing it would only push you closer to the edge of the cliff you couldn't scale back from. Twilight gives you a satisfied-looking grin, which she shares with Trixie.

"You've both been very well behaved," Twilight says. She reaches down and strokes the part of your cock being squeezed by the magic cock ring, and you feel a shiver run up your back and along your shaft, your balls aching to let out the pent-up load that's been building since you walked into the shed and saw Trixie writhing helplessly in the center. Twilight gives a few extra strokes for good measure, then returns her attention to Trixie, rubbing the poor things chest and stomach and nibbling on her neck and ears.

Trixie's a mess, she's not even speaking coherent sentences anymore, it's a wonder how she hasn't collapsed into a quivering pile, and yet here she is, still holding out...

"Go ahead," Twilight says, half-whispered into Trixie's ear. She reaches down to rub the blue mare's clit and at the same time shoves your hips forward with a jolt of magic from her horn, glowing lavender. You feel yourself bottom out in Trixie's cunt at the same time Trixie opens both eyes wide, her mouth as well, and stares up at you like she's about to break apart.

"Cum for me," Twilight whispers into her ear.

Something like an 'Ohhhh' comes out of Trixie's mouth along with the other sounds, but they're less transcribable, and the overall sensation of her isn't to communicate something through speech, but with her whole body.

You catch yourself staring first at her face, which is uniquely contorted, possibly the only way a pony can look after hovering on the edge of an orgasm for over an hour. It's a look of pained, absolute relief, but also of shame, of indulgence and hubris and just that perpetual feeling of 'naughty', that she knows just from one last thrust and a diddling of her clit that she's been sent over the edge, and there's no going back to a place of restraint anymore, this is everything now, and Mistress Twilight is in control every step of the way, pushing her even further forward, the eventual slobbering over-sexed fuck-machine she's being turned into played out by steps and series of instructions. Get Trixie to beg for it until she could beg no longer, then drag out the game longer each day. Eventually Trixie would be the perfectly trained pet, able to cum on command whenever Twilight wanted her to.

A human fit into all of this too, some other piece of the puzzle or a companion pet. You almost forgot the instruction was for you too, your eponymous tool serving its purpose a little too literally. At some point you come back into yourself, back into the body that's hunched over Trixie with your cock slid all the way inside her now. The way she clenches is like she's trying to wring out every drop of cum in your balls, and it's so intense it almost doesn't register at first, until suddenly you're sure you're cumming, your cock is twitching, jerking, all the cum that would be pumping out of your balls... except it isn't. Trixie's wet, and slippery, but she's not sticky yet, and she's still writhing in the throes of her first orgasm stretched into a long and continuous series of nonstop cumming.

"Here," Twilight says. Her horn glows, and Trixie's restraints unfasten, and for a moment you're sure she's going to let the captured pony lose to finally indulge her overwhelming instincts, but as you watch, Twilight simply flips Trixie in the other direction, onto her stomach, now facing toward the wall. She spins her right around without bothering to move her off your dick, so you get kind of a little spin-round inside her cunt as a treat. You're still in place, still just have to push forward to fuck her from behind now, but Twilight has a better place at the end of the boarded restraints, she can proper herself up next to Trixie's head pillow and get all the tongue-lashing attention she wants. Trixie's tongue is hanging out of her mouth anyway, it's probably not much trouble for Twilight to just put herself there and occasionally enjoy the attention on her pussy. But she puts a hoof to the back of Trixie's head again, to guide her, gently, perhaps, and the continuous sound of Trixie's orgasm is muffled again by her Mistress Twilight's cunt. Twilight lets out a moan too, and it mingles with the sound of Trixie's long, tortured-sounding orgasms, the pent-up result of an hour of edging with no release.

At some point during the encounter, an 'orgasm' stopped being a singular thing, now stretched out into the fabric of experience like a cohesive glue. You're cumming, Trixie's cumming, Twilight's about to cum... and yet all of this wrapped in a veneer of self-control. Twilight's control, more precisely. Even now, her hooves move to your shoulders, drag you forward and lock your lips into a kiss, you can't tell how much of the taste of Twilight's tongue is the sex and sweat in the air and how much she's personally attended to, but it doesn't matter, this is all part of the three of you moving together, working and attending to each other's desires. Once Twilight put the cock-ring on, your cock became more or less her property, and Trixie's been down that road long ago. Now all that's left is—

"Your Mistress is going to cum again," Twilight says, murmuring it almost to herself. She mumbles it into your lips during the kiss, and you're not sure if she's referring to you or Trixie when she says 'your' Mistress, but in the end, maybe that doesn't matter too much either. You keep your cock working in and out, your hips back and forth, concrete but abstract in your awareness of the thick load of cum brewing up in your balls, wondering when you'll get to let it out. You stare at Trixie's butt as you fuck her from behind, watching the playful bouncing of her bluebell cheeks. You stare at her tortured expression, her body wracked into indescribable states by overwhelming pleasure. You work your tongue inside Twilight's mouth and she returns your aggressive affectionate attention, kissing back just as hard, grabbing the back of your head and moaning muffled 'mhns!' into your mouth. Again, the air grows tense, the last few seconds of hot air before lightning builds from the ground and strikes backwards into the air.

Twilight cums with a sound like "—!". The sound of Trixie's continuous orgasms is best recorded by long, unbroken vowel chunks. You don't say anything besides maybe a few grunts.

It's easiest to watch Twilight, ride along with her rhythm as she rocks her hips back and forth, variously pulling away and squishing her sopping pussy into Trixie's mouth. Trixie keeps licking and moaning autonomously, theoretically on autopilot, maybe even requiring a direct order to return to normal function. You can tell Twilight's done cumming as she keeps riding, savouring the little aftershocks, just enjoying the soft grind of Trixie's tongue onto her clit. Then finally she pulls away, with a loud sigh, and you catch yourself doing the same, while Trixie gasps in air like she's forgotten to breathe for the last ten minutes.

Your three bodies collapse variously into exhausted sections of your continuous fucking. Twilight finally undoes Trixie properly, lets her get some air on her tied up limbs and move her body around properly for the first time in who knows how long. The pillows she's been resting on are soaked, and Twilight conjures a soft blanket and new set of pillows for the three of you to tumble onto, which you do, in short order, and without need for directions.

Still, as the three of you are lying there, you can't help but feel an insistence still bubbling somewhere. Your cock is still painfully stiff, and there's the matter of that tye-dye rubber ring affixed in a certain place. Your fingers move to remove it, but after a little scrabbling at the tiny accessory, find it firmly lodged in place. It doesn't seem to be going anywhere without Twilight's approval.

As if on cue, Twilight notices your attempt to dislodge the device and smirks.

"Now now," she says, the hint of authoritarian mischief already pervasive. "I don't recall giving you permission to take that off. Do you?"

"Well, uh, I guess—"

Twilight winks, and the ring tightens in a swift, single motion around the base of your cock.

Finally, your balls seem to say.

You get a little dribble of precum out the tip first, just enough to prepare yourself to tilt your pelvis in Trixie and Twilight's direction.

Suddenly, you're intimately familiar with the feeling that caused Trixie's face to become so hilariously distorted.

Your balls start emptying themselves in the direction of the two ponies lying next to you. Twilight giggles and almost bathes herself in the sticky white spurts, letting it dribble all over her mane and face, laughing and rubbing it in like a facial cream. Trixie's reaction is more subdued, she mostly just lets herself be the general target for half the load, getting hit pretty much everywhere in her prone position, ropes of cum exploding over her chest and stomach and dripping inbetween her legs, over the curve of her ass outlined by one outstretched leg... she gets a decent amount in her face as well, but her eyes are closed, so she doesn't seem to mind, or notice much. She does stick out her tongue, though, to lick a particularly lage glob off the bottom of her lips.

If possible, you'd collapse somewhere even further below your current center of gravity. Instead, you just fall down onto the blanket and pillows, and land with your head somewhere on somepony's legs. Your eyes are closed. You can't see who.

The whole room reeks of sex. A special indicator somewhere in the background has changed. Trixie's body curves up and down with each deep breath. Your cock, while still excited, is exhausted, and threatening to file for leave in the future.

Twilight lets out a sigh and smiles to the room in general.

"Fifteen minute break," she says. "Then we'll go for round two."

Turns out being a librarian's assistant can be a lot of work, if you know the right librarian...