https://boards.4chan.org/mlp/res/16315151#p16467198

The first thing Bundle Joy noticed when she woke up was the darkness. It was odd, as she knew her bedroom had a window, and not even the moon or stars were shining through. Her bedroom was on the east side of the house, so her room should be fully lit by sunlight.

The next thing she noticed tipped her off that something was very wrong. There was a collar around her neck. It was loose and padded enough that she hadn't noticed it at first, but it wouldn't fit over her head no matter how hard she tried. As she fought to remove the collar, she heard a jingling, and her hoof touched something metal that felt like a dog tag.

She groggily lifted her blankets and got off the bed, noticing a leash was attached to her collar, the other end of which seemed to be attached to the ceiling. She tested its limits and found there was nothing, not even a wall, in the exploitable circle besides her bed. Wait a second…

Her eyes had tried to adjust, but it was pitch black. She felt her way back to her bed, which seemed to be in the center of the circle, and sniffed her sheets, and found no trace of the trademark estrous musk she would've expected. Well, that pretty much settled it; she had no idea where she was. Out of ideas, she called out.

"Hello? What's going on? Mom?"

There was no response, so she raised her voice.

"HELLO‽"

Still nothing.

She returned to her bed and started inspecting everything she could to try and find an escape route, but came up empty. Eventually she gave up and collapsed on the bed. With no way to pass the time, she lay there for what felt like hours before she heard a click and light streamed in from an opening door.

She turned her head and saw the silhouette of a pony. As her eyes readjusted, she could tell it was that of a stallion. He chuckled.

"Ah, I see you're awake. Good. We should get started."

BunBun was confused, and angry. "Get started with what? Where am I? Who are you?"

The stallion chuckled. "Quite an inquisitive filly. Good, I like that. Anyway, to answer your last question first, you can call me… Dr. Q."

Bundle Joy was having none of this crap. "I'm going to help you take over the world, 'Doctor Q'. I don't know what kind of world-domination scheme involves foalnapping a random filly, but it'll never work!"

Her response was met with laughter, but not the evil kind. It was an undignified guffaw that continued for quite some time. Finally the stallion managed to catch his breath, and spoke. "Let there be light!"

Her room gradually lit up, and she looked around, getting her bearings. She couldn't see any lights; all of the illumination seemed to be coming diffusely from the walls themselves. Or rather, the wall and ceiling. The room she was standing in was a smooth dome roughly 25 feet in diameter. Neither the floor nor the ceiling had any markings; she couldn't even see where the door had been.

She looked back at "Doctor Q", who was still giggling. He was a full-grown stallion with a white coat and a slick black mane. Her eyes adjusted to the light and she made out his cutie mark, which seemed to be a bunch of lines. There were two thick lines, one vertical and one horizontal, with arrows at the ends, and a bunch of shorter, thinner lines in a grid pattern, all pointing different directions but following a pattern, like iron filings around a magnet.

The stallion sighed wistfully. "Oh, BunBun. You need to stop reading all those Daring Do books. I'm not a supervillian, and Doctor Q isn't an alias." He lifts a hoof and points at her. "Take a look at your tag."

She looked down and used a hoof to lift the silver-colored disk, which read "Property of Diffy Q".

Diffy continued. "You're probably wondering how I know your name, and the answer is very simple. I didn't just foalnap a random filly; I chose you, specifically."

BunBun was worried, but intrigued. "Oh? I'd ask why you picked me, but you still haven't answered my earlier questions."

Diffy smiled. "Oh, right, we got distracted. Where you are, well, let's just say it's your new home. What we're about to get started with is related to why I chose you. I'm about to mate with you."

Bundle Joy's eyes went wide. "No, please don't! I'm in heat!"

Diffy nodded. "Indeed you are. Just a word of advice, you never have to tell a stallion you're in heat. The whole point of estrus is to advertize to every colt and stallion in the area that you're ready to be bred. Anypony with a nose can tell when a mare is in heat, even if she tries to cover it up."

BunBun groaned. "Yes, of course I knew you knew that. That's especially true for me, 'cause m–"

"Your estrus is very strong. Yes, I noticed. It comes with your special talent, does it not? Your increased fertility?"

BunBun's eyes widened once more.

"Yes, I've learned quite a bit about you through the grapevine. You earned your cutie mark soon after your first estrus after conceiving triplets through non-penetrative sexual intercourse. Soon after giving birth to them, you were forcibly impregnated with twins by one of your classmates. You then gave birth, and have now entered estrus for the third time. That's where I come in."

Bundle Joy backed away in horror, the realization dawning on her. She glanced down and saw his sheath twitch, the shaft of his horsecock starting to emerge.

A grin spread across Dr. Q's face. "Yes, I have decided to breed you. Antiderivative only got two foals out of you, but I think I can do better."

"But… why?"

He just shrugged and stepped forwards, his stallionhood still growing. "I guess it's just a kink of mine. A boring answer, sure, but there's not really much more to it than that. I'm going to enjoy having such a fertile broodmare all to myself. Well, broodfilly, but you'll be a mare soon enough, and then you'll be my broodmare. This is your new home, Bunny. We're going to make so many foals here."

Bundle Joy felt terrified and powerless, but chose not to show it. "I'm not having foals with you! I don't know you, and I've decided to wait before having any more foals. And don't you DARE call me 'Bunny'! Tha–"

"Yes, yes, your coltfriend gave you that nickname. And he left you after you got your cutie mark because he couldn't afford to stay with someone with your talent. Well, as Royal Mathematcian to the Royal Pony Sisters, finances will never get between us. Besides, I think it's quite apt. After all, we'll be breeding like rabbits."

BunBun shook her head as she watched his throbbing cock grow to its full size. She eyed the drop of pre forming on its tip as if it were deadly irradiated toxic waste. "No, I…" She grunted as she was cut off, which seemed to be becoming a pattern.

"That wasn't a request, Bunny. It wasn't even a command. That was a simple statement of fact. You will stay here, and you will be my broodfilly. Every time you go into estrus, I will inseminate you and you will bear my foals. You will no doubt try several times to escape, and you will inevitably fail."

There had to be a way out. Her eyes followed the drop of precum as it grew large enough to fall to the matte black floor, splashing slightly before settling, a new drop forming in its place.

Diffy sighed. "Look, we both know how this is going to turn out. I've been planning this for almost a year now; there's no escape plan you can devise that I haven't already thought of and implemented measures against. So let's skip all this nonsense and get to business, okay?"

BunBun backed away further and reached the end of her leash, a few feet from the edge of the room.

Diffy just shook his head and looked up, lighting his horn.

She immediately felt herself being pulled by the neck towards the center of the room as her leash retracted into the top of the dome. When it stopped, her leash was no longer than the dome was high, allowing her a small amount of movement but not letting her move more than a foot from the bed.

Diffy began to casually walk towards BunBun, circling around her. Bundle Joy was terrified, and her heart was racing a thousand miles an hour. Diffy would've objected to such a meaningless expression, informed her of the distinctions between speed or velocity and frequency, and instructed her to use hertz for her next heartbeat-related hyperbole, but he did not. Despite all the power he held over her in this situation, he was not telepathic.

Diffy pointed to the edge of the bed and cleared his throat. "I don't want to hurt you, but I'll do whatever it takes to make sure you keep making foals for me. If you're coöperative, I'll be gentle."

She really didn't have any other options, so she did as she was told. She timidly walked over to where he stood and rested her belly on the bed, her back legs hanging off. She lifted her tail and braced for entry, realizing she was about to be skewered by a full-grown stallion's cock.

Dr. Q smiled and stroked her mane. "Good girl, Bunny. I think that deserves a treat."

At the word "treat", two large sugar cubes landed in front of her. Realizing she hadn't eaten anything since she woke up, she gobbled them up without a second thought.

Diffy chuckled and pressed the tip of his cock against her marehood. "Of course, sometimes the treats may be spiked with a fertility drug. You won't know when or how much. Maybe all of them are. But don't be surprised if you regularly find yourself carrying octuplets. You won't be leaving this room anyway, so mobility won't be an issue."

Bundle Joy just whimpered in defeat. His precum-covered cock was already pushing its way past her netherlips, so she knew they had passed the point of no return. Even if she somehow managed to subdue him and escape, he would still have won, as she'd indubitably get pregnant.

Diffy Q grunted as he pushed deeper inside her. "Fuck, this feels so good! I never would've guessed from how tight you are that you'd already had five foals. I'm going to have so much fun rutting you over and over without worrying about stretching you out."

BunBun gritted her teeth. He was thicker than any cock she'd ever taken, but still smaller than a foal, so she didn't feel much physical pain. In fact, he slid in quite smoothly, her tunnel already lubricated from her estrus. The flare of his cock slipped inside with a wet popping sound and she shuddered, trying to ignore the pleasure that was coursing through her body.

Diffy started thrusting, getting a little deeper each time. He felt his brood filly's body open up to accept him, inviting him in as a welcome guest, even as she lay whimpering on the bed, clearly unwilling. The feeling of her vaginal walls pulsing around his member was intoxicating, driving him deeper and deeper towards her womb.

Bundle Joy shuddered as he spread apart her walls and his cock forced its way deeper inside, an almost cartoonish outline forming on her lower abdomen. She tried to zone out, but each thrust brought her back to reality, and she found herself imagining her new life as Dr. Diffy Q's broodfilly, forced to mate every estrus until she got pregnant, and then some more just for fun. Never knowing when he'd slip her some fertility drugs and she'd carry a whole litter of foals.

Diffy moaned with satisfaction as he felt himself bottom out, just barely touching her cervix. He began to thrust in and out, his balls slapping against her clit, getting covered in her juices. "Wow, I can't believe I managed to get balls-deep in a filly your age. It's like our genitalia were made for each other." He paused, and then chuckled. "I mean, more than usual. Of course cunts are meant to get wrapped around cocks. Just like mares are meant to be bred." He grunts as he picks up the pace. "You should be proud, Bunny. Bearing foals is the most feminine thing a pony can do; a mare's fertility is her greatest blessing. And on top of that, it's your special talent! It's your destiny to have lots and lots of foals."

To her horror, Bundle Joy discovered that a part of her mind found she agreed with her rapist. Though rationally she knew she should be horrified and repulsed by the idea of being used like this, she still had this unshakable feeling that Diffy was just helping her fulfill her role and use her womb to its full potential. Her body seemed to know this; her vagina was eagerly wrapped around his invading member, coaxing him to unleash his cum into her fertile womb.

Diffy grunted and picked up his pace. "Fuck, Antiderivative was so right. You're the best fucktoy a stallion could ever ask for. So tight, but wet enough that I can slide just fine." He chuckled when her ears perked up at the mention of her previous rapist. "Oh, did I not mention? He's my son. One day he came home and 'confessed' to me, and I decided I had to try you for myself. Of course, he was broken up about it, but the naïve little colt just doesn't get that a mare's place is wrapped around a stallion's cock so he can inseminate her."

BunBun flinched, seeing more and more truth to his words. It *had* felt rather lovely carrying new life within her womb. She had been heartbroken when she hadn't been able to afford to raise her foals herself.

Diffy Q started taking slower, longer strokes in an attempt to delay his climax and give himself time to savor his first time rutting his new broodmare. The thought of her ripe young womb being forced to take in squirt after squirt of his thick pollen was the most exhilarating thing he'd ever felt. Like it or not, he was going to fill her fertile body to the brim with his cum, and she would carry his foals. And then she'd give birth to them, and he'd do it again. 40 GOTO 10.

BunBun moaned as she felt a heat burning inside her, begging to be put out. A part of her brain still wanted to run away and forget this ever happened, but that was being drowned out by the more primal parts of her brain. MUST BREED! COCK GOOD! NEED CUM! MAKE FOALS NOW! She had already lost to Diffy, but now she was losing her own internal struggle. Before she realized it, she was grinding back against her captor, trying to coax him to climax.

A satisfied smile crossed Diffy's face as he felt this. So, his new broodfilly had officially been broken in, huh? Rutting a filly who didn't want it was a great thrill, but he was relieved that he wouldn't have to worry about hurting her. He felt himself nearing climax, the slapping growing quiet as his heavy balls drew up tighter to his body in preparation to release his load. He knew it was likely redundant by this point, but he couldn't wait to empty his balls into her tight little cunt, officially marking her as his.

BunBun felt the change in Diffy's thrusts and tensed in anticipation, which only brought him more pleasure. She chupsed in pain as he slammed into her cervix, no longer careful in his thrusts, his animal brain telling him to thrust as hard and deep as he could. Then, she felt the sudden rush of heat as a shot of cum splashed against her cervix, quickly followed by another one. He was unleashing copious amounts of cum, even for a full-grown stallion. He'd probably been saving up for just this special occasion.

Diffy Q moaned as he shot another load of his thick cum into the quivering magnolia pony wrapped around his cock. He used his weight to hold himself inside her as he started getting pushed backwards, the earth pony filly's tight cunt formed a watertight (and, more importantly, sementight) seal around his spermworm.

Bundle Joy felt the heat inside her doused by the pool of cum building inside her. She didn't know if it was just her mind trying to rationalize the situation so she wouldn't go crazy, but she no longer had any doubts that this was how things were supposed to be. This was where she belonged, acting as a sleeve for a stallion's cock and a fertile place for him to sow his seed. He was just helping her fulfill her role as a mare. She'd never felt more feminine than she had right here, her cunt eagerly milking his cock for all he had, sucking him dry.

Diffy Q likewise felt all his doubts washed away. The power he held over this young filly was intoxicating, pure and simple. All he had to do was hold her still long enough to get his sperm into her, and she'd be stuck carrying his foals for just short of a year. While the mares had climbed to the top and taken control of most of the government, any stallion, no matter his rank, could remind any mare of her place with a good dicking. It was good being a stallion.

Bundle Joy's mind drifted away from the blissful warmth building inside her, and she thought back to her other two pregnancies. Sure, they hadn't been planned, but his they started was irrelevant. She remembered them expanding her little belly as she gave them a warm, safe place to grow. She had nourished them all from the moments they implanted, and named them all.

Though yet unborn, they had still been her foals, and she had been the best mother she could, singing to them and playing with them through her belly. She remembered the joy she'd felt when she could first feel them move, at first just a flutter, and later obvious kicks, her comically stretched young belly bulging and rippling like a pot of boiling water. And now, she got to do that all over again; in fact, being pregnant would become her default state, and she'd never have to give up another foal. In a way, she felt bad for Diffy Q, who could never fully experience the joys of motherhood. It was good being a mare.

Bundle Joy's eyes shot open as she was thrown out of her reverie. The pressure between his cock and her cervix had reached a critical point, and a winner had been determined. As his cock refused to budge, and his cum certainly wouldn't go back into it, her cervix had opened to relieve the pressure, instantly being flooded with his hot cum. It was an odd feeling, the warmth rushing into her very core instead of pooling against her cervix and seeping in as it usually did. Still, it was deeply satisfying to feel her womb distend slightly as it collected the hot, thick cum of her new master.

Diffy chuckled as he felt this, his cock bottoming out again as the pressure suddenly dropped. The last few shots of cum were shot directly through her cervix and into her hungry womb. He smiled as he forced the rest of his cum past her cervix, which closed back up as he pulled back, his softening cock easily sliding out of his new broodmare.

He stood back and admired his work. Her juices had run down the sheets, soaking them and matting the fur of her hind legs. To his satisfaction, none of it was mixed with his cum; she had been so tight he hadn't spilt a drop. The rest of her was soaked in sweat, and she was twitching slightly, clearly coming down from an orgasm of her own. She rolled onto her side and he saw a slight bulge in her belly as the tiny filly's body struggled to hold the deposit of a full-grown stallion after saving for several months. She was so beautiful, and she was all his.

BunBun sighed and laid a hoof on her belly. It was quite firm, and wouldn't leak when she pressed on it. She was practically high from the rush of hormones she was feeling.

"Don't worry, Bunny. It'll all come out in time."

She nodded, and looked down at her dog tag again. She noticed something she'd overlooked before: it was upside-down. She should've been reading all the text upside-down, but it looked normal to her. Of course it did. There was no chance of her getting lost in a park, so the only one who would need to be reminded of who she belonged to was her. She curled up next to her new master and smiled. "Doctor Q, I submit. My womb is yours to use as you please."

He nodded and ran a hoof through her mane. "You know, Bunny, you should put your mane up in a bun; I think it'd suit you."

Irritated, Bundle Joy turned away slightly and pushed his hoof away. "Did you even hear what I said?"

Dr. Diffy Q chuckled and stuck out his tongue. "Well, you announced something that's been true from the start like it was news, and as if it had been a proclamation you even had the power to make. I didn't think stating the obvious merited a response. But yes, I am glad that you've finally decided to acknowledge that."

There was a pensive pause.

"Y'know, once you're pregnant I just might be willing to share you with my son. You two can catch up, we can do some family bonding, and I can teach him how to treat a mare." The mathematician smirked mischievously.

FIN