Cheerilee stood in Twilight’s upstairs bathroom, looking over the bottles she’d been given. Each bottle contained vitamin supplements more in line with an expectant mother than a health nut; the princess allowed no chance at any offspring the experiment resulted in to be of anything less than perfect health. The schoolmarm looked at herself in the mirror, nude from the waist up as she posed; she imagined herself with a swollen, pregnant belly and pondered for a moment. “Hmm, heftier breasts, thicker thighs, bigger ass… yeah, I could pull off the MILF look,” she said to herself, already certain that she was very, very fuckable; sure, she had a bit of pudge here and there, but a number of ponies said that was a plus. Many of those ponies were also the ones who had seen her kinkier side and certainly did not mind seeing her in a leather corset.

“I wonder if my gear will go in the lab,” she pondered, slowly dressing herself once more. Certain items were of high enough quality to warrant medical-grade storage and care, but the vast majority were entirely inappropriate for such an environment. Still, she’d be spending much of her time in the library, if not the lab itself, so she’d like to have her creature comforts; she had doubts about what she was doing, and if nothing else, having her usual toys would be a taste of regular life until all the strangeness leveled off. “I’m sure I can convince Twilight to let me.”

Her thoughts turned to the purple princess. Twilight, as enthusiastic as she had been, was not used to her new equipment; all she needed was a little motivation and she could turn the tables on the teacher. It was not often a unicorn used his or her magic to pin her down and rut her like a bitch in heat, but she rather liked it when it happened; the very thought of a repeat performance was enough to turn her on. She was being paid to do what she loved, and with no need for condoms or annoying birth control methods, she loved it even more; the fact the entire object of the sex was to get pregnant was a twist on a common fetish numerous mares had, and being stuffed with another mare’s foal added another tone to the kinkiness of the entire situation. She grinned as a familiar warmth bubbled inside her, an itch a certain princess would be all too eager to scratch.

With a devious glint in her eyes, Cheerilee walked downstairs, seeing no need to sneak. Twilight was in the kitchen trying, and failing, to make something other than chopped fruit for breakfast; she wore her usual combination of a blouse and slacks, protected from the mess she was making by an apron that was unfortunately covered in what could generously be called batter. The alicorn sighed and set the mixing bowl back down, drooping her wings in defeat as she puzzled over the mixture; it was then the cerise mare pounced.

“Hey!” Twilight yelped, entirely surprised by the hands squeezing her ass and shaft through her pants. Her words morphed into a squeak as she was bitten on the ass, gently enough to be more enjoyable than anything. She jumped and looked down, immediately recognizing the hand massaging her cock. “Cheerilee,” she groaned, hardening under the teachers ministrations; the groping hands and nibbling teeth didn’t stop, instead growing rougher as she responded. “I’m trying to make breakfast here.”

“I’d prefer something else, princess,” Cheerilee purred, unlatching from Twilight’s perky rear. In a flash, she’d undone the knot holding the apron in place and popped the alicorn’s trousers open; her breath hitched in her throat as she pulled them down, exposing a rather attractive area of Twilight's body. "As much as I love looking at you from behind, I want you turned around." The schoolmarm did not allow for choice, grabbing her prey’s hips and swinging them around; in an expert show of marksmareship, she caught the princess’s stallionhood, pursing her lips around its head as she looked into its owner’s eyes.

“I’m not complaining,” the princess murmured. Cheerilee was an expert at all things sexy, and the way she swirled her tongue around Twilight’s cockhead only reinforced the idea. She leaned back and allowed the cerise mare to work her magic, biting her lip as the teacher suckled on her tip; it wasn’t even a moment later that she was gasping every time Cheerilee swallowed her length. She rested her hands on the earth mare’s head, content to relax until she neared her peak. A devious thought entered her mind, something she struggled to resist. “Can, um, can you take me any deeper?” she asked, still unsure of how to use her endowment in its entirety.

Cheerilee only nodded before taking a deep breath, pausing only briefly to wink at Twilight before swallowing every inch of the princess’s cock. She flicked her tongue into the underside of the alicorn’s sheath and savored the sweet groans she heard; she was a pro at this, massaging the dick in her throat with muscles trained by years of experience. She choked a bit in surprise as once-resting hands gripped her head.

“I’m glad you don’t have a gag reflex, because I feel you’ve had this coming since you slipped out early yesterday.” Without hesitation, the princess pulled Cheerilee away; her horn lit up, sending tendrils of purple-pink magic to bind the teacher’s wrists and ankles. “Take a deep breath.” The earth mare did as instructed, more than a little aroused by Twilight's sudden change in attitude; without respite, the alicorn slammed Cheerilee’s face into her groin, forcing her cock as deep as it would go. The teacher was not sure what had possessed the princess to do this, but she decided it was not necessarily a bad thing; she winked at Twilight to let her know she wouldn’t do anything untoward, or at least anything that may result in unnecessary bodily harm. “I’ll try not to choke you; just shake your head if it gets to be too much.”

Cheerilee nodded as she was forced back, taking another deep breath just in time to keep from inhaling a large glob of precum. Drool spilled from the corners of her mouth as she was moved along the alicorn’s hard length, dripping from the well-polished member every time she was slammed back down. “Now I wonder,” Twilight began, twitching in Cheerilee’s throat. “Do I cum in your mouth, or over your face?” The princess puzzled over the quandary, ruthlessly fucking the earth mare’s face as she forced her orgasm near. She growled lustily as she reached the point of no return, her cockhead flaring inside the teacher’s tight throat. In the final instant, just before her release, she pulled back until only her flaring head was wedged inside. The edges of the princess’s vision went white as she came, muscles tensing as her dick twitched; Twilight gasped as her orgasm started, an unstoppable tide of endorphins flooded her body as she lovingly deposited her load in Cheerilee’s mouth, bulging out her cheeks and saved from spillage only by virtue of magic.

Time stretched on longer than it needed, turning seconds into a blissful haze as Twilight experienced her first orgasm while buried into something that wasn’t a cheap sex toy she ordered from a seedy catalogue. She whimpered as the teacher ran her tongue over her too-sensitive flare, feeling the reservoir of cum swish around before it disappeared down Cheerilee’s greedy throat. She regretted that her cock started deflating, regretted that she had to leave the warm confines she so loved right then; she gently patted the earth pony’s head and pulled out with a pop, still dribbling a bit of leftover semen as she flaccidly bobbed in the open air. “I really am glad you agreed to the contract, Cheerilee,”

“No thanks needed,” Cheerilee said, catching her breath. She was terribly aroused, arms and legs shaking as her pussy left a very noticeable mark in her panties, stuck fast against her plush lips as she trembled with the object of her desires inches from her face. “So, this means your going to knock me up, right?” she asked, voice barely a whisper as she imagined the feeling of hot cum exploding inside her. She enjoyed sex plenty, and had even engaged in some breeding roleplay with a stallion or two, even once in a threesome with Cloud Kicker where Cheerilee pretended to sell her off to some lout, but to actually offer herself up for the oldest and most basic function of life was just a bit exhilarating on a level she could not properly explain.

“If everything goes right, you’ll have a belly full of my foal as soon as you’re ready,” the princess said in the soothing, afterglow-tinged she always had after a good orgasm. “But, again, we have a couple of months until we’ll be skirting the date for conception if we want to be able to pay you.”

“Can… can we do it now?” Cheerilee wondered if she sounded as horny as she actually was, if the entirety of her needs were being fully conveyed. She looked up at the half-hard princess for her answer, only to see a slightly confused expression. For a brief moment, she was angry at the response; there she kneeled, wet enough to drown a fish, stomach full of warm cum, and Twilight had the nerve to keep standing there when she could have been fucking her senseless.

“Pardon?” the regent asked, cock bobbing in time with each syllable as the words sank in. It may have been the testosterone or some instinct that came with her new testicles, but something about Cheerilee asking to be impregnated stirred something primal within her; the fact it would be her foal only raised an odd taste in the back of her throat, like she was nervous, but so much sweeter. In the back of her mind, she tried to recall all the fertility spells she had learned, all the ones created to combat the very problem she was working against, until the one she wanted came to mind; it was old, old enough to have been made with the belief that mares determined the foal’s sex. Dark age of science or no, what the spell did ensure was that a healthy ovum was released, and like the powerful mage she was, Twilight cast it on her chosen partner without conscious effort.

Cheerilee, however aroused she was, knew the princess was getting hard again, her cock jerking with every heartbeat as it grew back to its full size. “I want you to fuck me,” the teacher huskily panted, wriggling in the magic bonds that still held her in place as she nearly soaked through the back of her skirt. “I want you to fuck me like wild animal.”

A growl rose through Twilight’s throat as she flinged Cheerilee onto her feet, still bound at her wrists and ankles, before throwing her onto the table. She certainly felt like an animal; she could practically smell Cheerilee’s pussy from where she was, and she hungered for it like a starving beast. The princess grabbed her prey’s shoulders and pinned her down while she poked and prodded around to find that delicious warmth that taunted her so. She rubbed her cockhead against a slick, wet patch but found no entry. With an angry grunt, she freed one hand to claw at the offending articles, tearing them away before leveling her flare with Cheerilee’s dripping lips. Without foreplay, without even a gentle nudge, she rammed herself as deeply as she could go.

The effect was instantaneous; the earth pony whimpered as she was split open, Twilight’s flared head wider than she expected, slick with cum and spit as it plunged into her depths. She twitched her hips against the invader, pressing back each time the alicorn thrusted, trying to bring her deeper than her delightful cock was; every bit of pre leaked into her felt like liquid fire as it burned a path to her cervix, where it puddled up and made her beg for more. The weight pressing down on her made it hard to breath properly, but it felt far too amazing to both resisting, so she squirmed and jerked like the good little slut she tried to be. Twilight hunched over her and buried her snout in her mane as she sped up.

“Yes! Cum inside me!” Cheerilee shouted, mustering all the breath she could. The alicorn above her growled and stopped moving, leaning over to rummage on the table for something while she kept the earth pony held down. Before she had a chance to complain, she was gagged, mouth stuffed with her own soaked panties as she felt the cock buried within her slowly shrink away from orgasm. She whined as best she could, but did not try to move her arms from their binds; it wasn’t her first time being punished in such a way, but she rather enjoyed being vocal. That familiar, almost comforting, snout buried itself in her mane again, inhaling her scent in a primal display of crude affection.

Twilight started back with the slow, careful patience of a burglar, easing in and out at a pace she knew Cheerilee would hate only for its gentleness. She clenched and wiggled around her, trying to entice aggression as the princesses worked herself back up; each measured movement teased the underside of her cock over Cheerilee’s g-spot with enough force to remind her precisely of what she was missing. Her control wore thin, eroding with every little noise Cheerilee made as she tried to piston herself over the princess’s rod; she herself could feel her own orgasm approaching, slowly, but with very firm knowledge of what awaited her, Twilight could hardly hold back. She rolled her hips forward, changing the angle of entry, and sped up just a bit, not showing the g-spot much attention but absolutely adoring every quivering muscle she rubbed against.

Cheerilee had asked to be fucked like an animal, and while that had been all well and good, but she was just a bit worried about hurting her; she never did enjoy being dominant, but that spur of the moment decision had been pleasurable, to put it mildly. “I hope you’re ready for it,” she whispered into Cheerilee’s ear, delighting in a hard thrust; the teacher moaned into her panties and nodded her head, laid flat against the table. The princess grit her teeth and gave up teasing, gripping her lover’s shoulders as she pounded away; bliss was just around the corner, just out of reach. Her pelvic muscles tightened as she neared her peek, shaft thickening and head flaring to drown the Cheerilee’s womb with her seed. Twilight's cock bumped against her cervix, and everything went white.

A gasp from the door broke her stupor; apparently Derpy had let herself into the library and walked in at either the best or worst of times. The alicorn looked at her, twitching as she unloaded inside Cheerilee, who was too out of it to bother with any greeting other than a bubbly mumble. “He-hey Derpy,” the princess squeaked out, embarrassed at being caught and still riding the high of her orgasm while she stewed in her own cum. With a wet popping, sucking sound, she pulled out, bringing a small flow of semen with her; it spattered on the floor and nopony paid it much mind. “I, uh, wasn’t expecting you to come back.”

“Spike gave me quite the sales pitch after I left,” the mailmare replied, fidgeting in place. “I’ll just wait in the foyer while you clean up, and then we can talk specifics.” She really did not want to discuss what she knew in front of Cheerilee, not after how she had acted. How was she supposed to know everything going on if the ad hadn’t specified.

“I’ll be right there,” the princess hastily said, using her magic to clean off her shaft while she buttoned her trousers. Twilight wondered why Derpy was back, given how angry Cheerilee said she had been the day before, but appreciated whatever Spike had done to make the mailmare see reason. She released Cheerilee’s bonds and stumbled into the front room with her dick half-out while removing spilled juices from her blouse. It was not an attractive sight, unless one enjoyed the sight or hermaphrodites slightly covered in their own fluids while reeking of sweat and sex.

“So...,” Derpy started, trailing off as she lost her words. She politely allowed Twilight to cover herself properly before continuing, surprised at how strange she felt actually seeing everything going on, even after Spike had tried to explain over breakfast that morning. “Spike came over yesterday afternoon and convinced me to come back,” she said, lying only about the time Spike had spent over. While perfectly legal, the experiment required Derpy to have avoided sexual contact for a period of weeks before the final interview, and as some internal bruising as a dirty set of sheets attested, Derpy Hooves had been a very bad mare in that regard. “So, you;re going to do to me what you've already done to Cheerilee?”

“Spike told you everything?” the princess asked, a bit worried somepony could have overheard them while at her house; while they had the princesses’ permissions and pardons laid out for them, the official actions that had to be taken would ruin the reputations of everypony involved.

“He stopped before the story got to the delivery room; I’ve been often enough to know what happens in those.” The joke was dry, but not untrue. Derpy leaned over and rested against a bookshelf, legs still a bit tired and certain parts were a bit sore, but not uncomfortably so. “So, we’re breaking the law for a good cause?”

“The very best!” the perky princess quipped, mustering a smile. “I know, I know, it seems like an odd solution, but I have my own hypotheses about what’s causing the sex gap,” she paused for a moment while the crude humor settled in, “and with the work I’m doing, not to discount Cheerilee and yourself by any means of course, we should have Equestria back on track to balanced numbers.”

“And the money? I have a family to feed as I’m sure you know.”

“Handled, fifty bits per day for the duration of pregnancy, and one hundred-fifty per week for childcare expenses afterwards, should you choose to raise him yourself.” Twilight honestly hoped the foals would be raised in town; she had grown rather attached to the idea of being a… parent over the days leading up to her true trials. The thought of a pair of bright-eyed rambunctious colts running around and calling her mommy made her tear up a bit, but she did her best to maintain royal decorum. “Oh, and all medical and prenatal expenses will be taken care of. You also should not worry about one of your foals getting sick or hurt, because I’ll be paying for that myself.”

“Sweetening the pot?” Derpy asked,looking unamused, but relieved that she could stop worrying about her family’s bills for the time being.

“Canterlot School of Business, graduated while I was still Princess Celestia’s student studying magic,” Twilight said with a smug smile. She knew every little thing she needed to do and say to keep a business running, and thankfully she understood enough about employee fringe benefits to know that she could cover nearly anything. “And don't say I’m crafty; I just care a lot for Equestria and her citizens, and this is a better way of helping everypony in the long run than fighting monsters ever was.” She crossed the room and stuck one hand out in confidence. “Is it safe to say you’re all aboard for this?”

“We still have some kinks to work out as far as actually making the foal goes,” the mailmare answered, shaking the offered hand firmly. After a brief moment, she looked down and grimaced. “That can wait until after you've cleaned up everything.”

“Right,” Twilight agreed, looking over herself once and turning to check the kitchen. “I think I’ll go shower... and grab a mop,” she groaned, hoping semen came out of hardwood floors without too much effort. “Just make yourself at home, check upstairs or the basement if you want, and if you need anything, don’t hesitate to ask Spike, if he’s even awake right now.”

“Sparkler’s the same way about getting up early,” the pegasus chuckled. “Go on and clean up, I’ll make myself comfy.”

_-_-_-_-_

Spike, in all his years of life, had never had to break into his own home, but as he tumbled through the basement window and fell onto a pile of old books, he came to the understanding that breaking and entering was not a career choice he should ever make. He rolled off the literature and walked around the display of sex toys and instruments he affectionately called the lab and made his ways upstairs. He kept an ear to the door for a while, listening for anypony who may be around; as far as he figured, Twilight thought he was asleep, and he planned on keeping it that way. He was going to follow his morning routine flawlessly before entering the library, albeit a bit later, but that was because today was a lazy day. He would speak to Derpy later; he needed to get into a shower before Twilight worried about him.

Author's Note

Right, gents, sorry for the delay, and apologies if this has not lived up to your expectations.
Consider it an early Christmas gift from me to all of you.
I haven't been anywhere near horny enough to write for this story lately, but I finished this chapter up in about a total of two weeks after getting back into the swing of writing again, so maybe, maybe I can update again with some sense of punctuality next time.