Twilight was at the monthly 'heat-party' breeding orgy that Pinkie held during the mating seasons every year, having applied the contraceptive spells to all the mares who wanted it, and now staring at the goings-on; stallions mounted on mares and humping away, mares riding stallions' cocks as they laid on the provided cushions, and mares using dildos, other toys, their hooves, or magic on their mare partners, all accompanied by the sound of techno music throbbing through the speakers and sounds of pleasure.

Twi knew that many of the mares with stallions were being truly bred, having refused her offered contraceptive spells, and that only made the whole scene that much more sexy to her; she never knew if a stallion's cry of orgasm was a mare being given a foal or not. Twilight was standing in the corner as the music only partially drowned out the moans and cries of passion and orgasm...before something weird happened.

All of a sudden, all of the stallions, and even some of the mares, became Bade Moonglade and many of the mares became herself, making Twilight gasp softly as she looked around, seeing Bade mating her in so many positions, or using so many different toys on her. Finally, one of the Bade clones walked up to her and mounted her suddenly, Twilight moaning out in pleasure at his weight on her croup, before he pulled back his hips and—

~

"Uuuugh..." Twilight moaned as she awoke the next morning with a dry throat and a throbbing head, groaning as the morning sunlight made her wince and turn away. Her whole body felt hot, making her kick off her covers, feeling the mattress beneath her soaking wet as though she'd lost control of her bladder...though she knew that wasn't the case. Her lower belly had that certain itchy-burn, and the air around her had that certain musky-neon scent that could only mean one thing: she was an alicorn in her estrus, her body and mind both begging her to find a stallion to breed her.

Twilight groaned at the horrible sensations, knowing they'd only get worse than better as the day, or days, went on; knowing that having a stallion around, especially one she may have...certain feelings for judging by that dream she'd just awoken from, would only aggravate it and make it go full-strength for five or more days, instead of her heat being weaker and fading away after just a day or two like it always used to. Not to mention the fact that he'd likely be distracted from his job by her fertile scent...

"Great... now I'm in heat and there's a stallion who may have a crush on me, and that I myself may have a crush on...not to mention a mare who's been trying to get me into her bed since day one, in my castle..." Twilight muttered to herself as she closed the blinds, silently cursing the sunlight for bringing her estrus on through no fault of its own. "Stupid estrus, stupid mating season..."

In the past, in order to avoid the breeding season and instead use that time to get ahead on her studies, Twilight usually locked herself away in her library, or now her castle, for a day or two to avoid the temptation of pouncing a stallion and having him fill her up with his big, long, hard—but now with her new guards here, especially the handsome, adorably shy Bade Moonglade, there was a temptation she couldn't simply just get rid of. She knew simply hiding in her bedroom wasn't going to work this time, and had already submitted to the fact that she likely wouldn't be a virgin anymore by the time this heat ended. Something she was actually surprisingly alright with.

"Bye-bye virginity, it's been nice knowing you..."

In the past weeks after her guards' arrival and even to that day, Twilight had also started studying on thestrals more, learning about their history, biology and general habits... and their courting methods, erogenous zones, and reproductive habits, just in case. It didn't help thinking about those particular lessons now though.

"Well, remembering all that certainly doesn't help my...urges..." Twilight groaned, her muzzle landing into her pillow with a quiet *pomph* as her wings stood erect behind her, her lower belly burning as her pussy leaked its nectar all over her bed while her clit winked constantly at nothing.

Twilight moaned as she thought about all she'd learned about a thestral stallion’s 'reproductive anatomy' and the diagrams of them in the books, her hoof creeping down her barrel until it met her heat-swollen marehood lips, making her gasp as she realized just how wet and sensitive she'd gotten, no doubt from that heated dream she'd just awoken from. "Wow...almost forgot how wet I get down here during heat with other ponies around...and hot..." Twilight muttered as she started passively rubbing and spreading her lips to dig a little deeper, moaning softly as she did, "a-and sensitive..."

Twilight knew that rubbing herself to orgasm would only help slightly for a couple of hours at most, even in the best of times, even alone and without a virile stallion in the same building. Regardless, even a few minutes was better than no relief at all. Plus, masturbating and cumming felt great no matter what, especially when enhanced by her increased sensitivity from her estrus.

"I bet Bade's cock is waaaaaay better than just my hoof... I mean, it can probably go all the way inside of me after all...I wonder if his looks the same as those in the books..." Twilight said, her face instantly flushing hot as she thought that against her will.

"Stupid heat!"

~

As Twilight stepped into the shower after a fairly underwhelming orgasm in her bed, though all it achieved was absolutely soaking herself and her bed with her very thick, fertility-telling fluids when she came; she still felt the burning inside of her just as intensely. Her climaxes were never truly satisfying, but instead extra messy and hard to clean up after, during her estrus. She always felt so empty as her muscles clamped down on nothing when she orgasmed...all alone...

Twilight gave a quiet gasp as the cold water washed over her, cooling her off almost instantly...except that incessant burning in her belly and crotch, of course. She stood under the cold water for a long while, simply letting it run over her as she thought; thought of her new guards, and especially of Bade. As she thought more and more about Bade, she found her belly burning hotter every time she thought of him or her dream which just wouldn't fade from her memory, her nether leaking its precious nectar as her clit reflexively winked near-constantly, making it run down her legs or directly onto the shower floor, then down the drain with the water.

"I need to orgasm again...already...?" Twilight asked her winking marehood flatly, though it gave no response besides another desperate couple of winks, "Fine..."

As she finished in the shower, and after she brought herself to another unsatisfying, overly-messy orgasm with her hoof thinking of her sexy stallion thestral guard whilst the water washed over her, she walked to the dining area, following her nose to the food she'd been smelling. Then she saw him. Bade was innocently sitting at the breakfast table having some pancakes and eggs, laughing at a joke Amaya had told and she'd apparently missed, totally unaware of what was coming. Almost instantly he stopped laughing and Twilight watched his nostrils flare as his head snapped to her once she'd entered the room, his nostrils flaring more as he sniffed more on reflex, subtly taking in her fertile scent as he felt his sheath stirring in response.

"Good morning..." Twilight said groggily, not oblivious to the, likely sexual from one and obviously sexual from the other, attention that she was getting from the other two ponies, Spike apparently having left to do whatever he chose to do outside of the house after making breakfast. Likely something involving his marefriend Apple Bloom in some, likely physical, capacity given it was pony mating season after all. Twilight poured herself a much-needed cup of coffee with her magic, groggy even still after the cold shower, and still feeling that burning within her that was only aggravated more by being in the same room as a stallion. A stallion who, judging by his lightly-musky scent, was very virile.

"Um, good morning Twilight." Amaya replied, not oblivious to the sexual tension now palpable in the room, nor the scent of mare-in-heat that she knew was not coming from her, the only other mare in the room.

Bade nodded but remained silent, nostrils still twitching, afraid he'd give off a breeding whinny instead of a 'hello' if he opened his mouth.

Twilight took a long swallow of the still-warm coffee, giving a quiet 'mmm' as the strong, bitter brew flushed her senses of the scent of stallion musk and her own heat for but a moment, before both were back in full force. "Bade," Twilight said, getting a jump from the dazed stallion, "I um...after breakfast you...I'd like you to guard me while I'm in my study today. I don't want any interruptions as it's a...very delicate study I'll be doing today, and you seem like the...perfect stallion...I mean pony...to do that." Bade simply nodded, internally wondering why she was changing his post assignment so suddenly....and why she was so nervous about it. After all, now was usually his off-duty time.

"Amaya, I'd also like you to guard the outside of my castle and prevent any intrusions or interruptions to this...delicate study."

"Yes ma'am!"

"Yes ma'am!"

After a tense breakfast was finished, Bade's eyes almost never leaving Twilight and Amaya offering a suggestive gaze of her own at the heated princess, Bade was now standing outside of Twilight's study in full armor. He stood stark still and staring forward, on-duty. He knew Amaya was patrolling outside as ordered and couldn't help but feel slightly guilty that she had the harder job. However, his thoughts were interrupted. "Bade?" Twilight called out from within the room, "Can you come in here please, I need help with something."

Bade hesitated, knowing only one way of 'helping' a heated mare, but quickly heard her demand again.

"Now, please."

Bade opened the door and, as he feared, was smacked right in the muzzle with the pheromones of a very fertile mare. The whole room was saturated with Twilight's scent; the musky, lightly-neon-hinted scent of a ready-to-breed Alicorn mare calling to him on a very base level to come and mount her, apparently the same scent as a Unicorn.

"Oh, there you are! Come in....all the way please." Twilight ordered, with the stallion hesitantly agreeing and entering the room fully. As Bade did as ordered and closed the door, he looked up to the mare who'd called him. Twilight was sitting behind her desk on a cushion, before her a small stack of books and opened one, her scent coming off of her strongly; Bade knowing by her scent that she was likely to be ovulating within a few days. Nothing suspicious about that, as it was only natural. What was suspicious, however, was the look she was giving him. A look that basically said 'come rut me'. He simply dismissed it as subconscious on her part.

"U-um, yes Princess, how may I help you?" Bade asked, though not daring to imply the most obvious way he could 'help her'.

"Ah, yeah, that..." Twilight stammered out, her eyes shifting as she clearly was thinking, "AH! Well, I was just researching the Thestral race as you can see...and I thought it would help to have a live subject to do an...external biological study on. Nothing invasive I promise, simply...external structures and...appendages. It would likely involve me touching certain...physical parts of you, such as limbs and...appendages..." Twilight said, but her voice and gaze upon him were not changed from the earlier tone she'd used with him, the one basically saying 'please come rut me, I need your foal'...or was he simply imagining that because of her condition and what it was doing to him, Bade wondered.

"I, um, I suppose that's alright...as long as it's not 'invasive', that is." Bade simply said, though he almost instantly regretted the words as they left his mouth, knowing what letting a mare in heat touch him, even in a clinical manner, would likely do to him; what involuntary reaction would very likely happen with her fertility-telling scent so close to him, her touch on his body...

Bade stood still, awaiting his next order.

"Mmm, thanks for your agreement to this...strictly scientific study. Now first, let's get rid of this armor that's...impeding me." Twilight said, lighting her horn, before Bade watched as her raspberry-red magic worked to unstrap his armor, feeling his chestpiece going loose first, followed by his flank-pieces being loosened and removed as well, then his sabatons. Finally, his helmet was taken off, all pieces neatly placed in a pile...and leaving him completely bare before the Princess.

Instantly Bade felt her eyes trailing over his fully-natural form, Twilight clearly taking in every aspect of him. For science, of course. Not like she was checking him out or anything. "There we go..." Twilight cooed, "...now...let's see...the subject is a stallion thestral and is about twelve hooves* high, fairly tall for an average pony stallion, and likely weighs about one thousand, five hundred pounds given his...very muscular physique." Twilight noted in a pseudo-detached, pseudo-clinical tone, using a measuring tape to measure him; Bade could still hear that tone of seduction in her voice however, no matter how she tried to hide it. "Subject 'Bade' is very fit and is a stocky build, a prime candidate for the study..." Bade noted that she paused after giving emphasis to that word, looking him over again, before continuing, "...and as such, I'm very lucky to have him agree to help me."

Again, Bade noted her emphasises.

"Bade, can you please open your wing to full length? I'd like to get a measurement of your wingspan now," Twilight asked, and Bade obliged, his wings unfurling and opening with a quiet flapping sound, feeling his slightly-cramped muscles pleasantly being stretched as he did. Bade felt the cool fabric of the measuring tape on his wing, even that clinical touch to such a sensitive area once more testing his ability to 'keep it in his sheath' as a tingle of pleasure went down his wing and then spine from the touch in his aroused state, as well as him hearing the distinct scraping of a quill on parchment. " Bade's wingspan is about twenty hooves wide, which actually exceeds his height." Twilight observed, before moving to his side.

Bade unexpectedly felt the measuring tape press softly to his neck, then felt the other end stopping and almost slapping his rump, feeling it pressing into the sensitive flesh of his Cutie-mark, making it that much harder to hold 'himself' in. "The stallion's barrel is about seven hooves long as well, meaning he's about half as long as he is tall, as with most other ponies." Twilight said, before suddenly reaching up and pressing her hoof to his stifle, rubbing it.

"H-Hey!" Bade responded in a surprised tone, feeling Twilight's hoof quickly retreating from his rump.

"S-Sorry!" Twilight stammered, "I just wanted to see if thestrals' Cutie-marks are as sensitive as a ponies' are. Apparently they are. I...um, I'm sorry? I guess I got a little...caught up."

Bade could sense by her expression that she wasn't sorry at all, and more than half wondered if it wasn't an intentionally sensual touch. Of course not though, that would be silly. Twilight, a Princess, being sexually attracted to a simple thestral guard simply was not possible. Was it? Besides, this was a scientific study, she'd said it herself. Of course, her own sexy alicorn wings being fully open and erect like that likely wasn't part of the study...

"I, um, I was curious if I could...touch your wing next? I was kind of curious about their sensitivity and...texture as well." Twilight commented, her blush actually starting to form at the request, "I...I mean if that's okay."

Bade was getting very suspicious now, with a thestral's wings being very sensitive to touch and indeed an erogenous zone much like how Pegusus wings are, and the fact that they are generally only touched during sexual foreplay or sex by a mate or personally for cleaning; given the lack of a need to 'preen' them as feathered wings had to be, the thestral was simply able to wash them in the shower like any other part. "I, um, I guess that'd be OK...for your study, that is." Bade said, quickly feeling his wing softly being tugged by her magic to open, before he personally opened both wings to their full span.

"Wow, they're beautiful!" Twilight exclaimed as she saw his wings open in their full glory, with them arching slightly upward from his back unlike a Pegasus's that stood up nearly straight at full expansion. Backlit, the thin grey membranes were slightly transparent, the forearm and fingers of the wing being a darker grey, like his coat, than the membranes. Hearing her call his wings beautiful made Bade smile slightly in pride, thestrals being just as proud of their wings as their Pegasus brethren.

"Um...thank-aaah!" Bade said, interrupted mid-thanks by Twilight's hoof tracing his wing’s membrane with a hoof, making pleasant sensations crackle throughout his wing and up his spine... and to his underbarrel as well. "C-careful please, our wings are very sensitive..." he warned softly, getting a nod from Twilight.

"I know, sorry." Twilight said slowly, then methodically traced seemingly every inch of his wings with her hooves, membrane and finger and forearm alike, Bade trying his best to keep his resolve and keep his penis inside its sheath, his guard training helping but clearly not much. That, however, was not meant to be.

As Twilight started to rub the muscles that attached his right wing to his barrel, Bade winced as the stimulation of those very sensitive muscles, mixed with the scent of a receptive mare and unintentional, or so he thought, sexual teasing, had its effect. He felt his penis drop against his power and the cool air of the room wash over his flare, with him sweating now from the surely-unintentional sexual teasing Twilight gave him, swiftly growing harder as she continued the wonderful, definitely-not-sensual massage.

"...and what is this Master-Sergeant Bade Moonglade? Indecent in front of a superior officer?!" Twilight virtually cooed, clearly having seen his peeking 'little soldier'. Though oddly, her voice was still seemingly seductive.

"M-MA'AM, I APOLOGIZE MA'AM!" Bade immediately exclaimed, panicking through the pleasure, her rubbing on his wing's base not having stopped, and as such he continued to grow harder at the stimulation.

"Explain yourself."

"Ma'am, a thestral’s wings are mmmph an...erogenous zone, ma'am, and you're rubbing mine. It’s also m-mmmmm-mating season ma'am and you’re giving off pheromones, and it's a s-strictly involuntary reaction, I swear to you ma'am!" Bade desperately tried to explain, sweating heavily now, hoping and praying to the goddess Faust that Twilight's punishment would be lenient. He expected to be banished from Equestria, to be sentenced to a life of dungeon time...

...the last thing he expected to hear, however, was Twilight giggling.

"You sure it's totally involuntary?" Twilight asked, Bade utterly surprised by that question, "Because to me, it just looks like you're submitting another 'appendage' to be measured..."

Bade's jaw hung open. "M-Ma'am?" he asked, utterly baffled.

"Well, I did say I'd be studying your appendages, and I'm pretty sure your penis fits in that category..." Twilight said, giving another unbelievably sexy giggle, "...but I'm afraid I can't tell its true length in its semi-flaccid state." Twilight said matter-of-factly; "I need it to be...erect."

That statement alone got Twilight that much closer to that goal, a throb going through Bade's very alive 'appendage'. "I...uh...?" Bade stammered, now at a total loss for words, feeling his semi-boner lightly twitching in response.

"...and what better way to get it fully erect than...direct stimulation from a mare in estrus?" Twilight's voice oozed lust now, even if it was poorly covered up by mock indifference.

"W-wha-are you saying..."

"Stimulation by hoof...and maybe more, if needed."

Bade's face was beet-red at this point, not sure how long he could keep up the thinly-veiled charade Twilight seemed to be playing. He could feel her lust just as strongly as he could smell her growing, needing scent, yet she still kept up the medical act.

"O-okay, that's okay I guess." Bade stammered, and then felt Twilight gently nudging him towards the desk.

"I'd like you to lay down so I can...'study' you more thoroughly. We can use the desk as an examination table; it's nice and sturdy." Twilight said, nudging him with her muzzle and him following her direction.

"B-but the desk is full of books and..." Bade stammered...only to watch as a wave of raspberry-red magic swept everything to one side of the desk, everything from books to ink-pots to quills haphazardly dumped into a large pile now.

"There, now it's not," Twilight stated flatly, "now please lay on your back on the desk."

Bade wasn't sure if he was taking orders from his princess anymore or the horny mare she'd become in her estrus, but his penis gave a throb in favor of the latter. Not one to disobey a superior's orders, he climbed on the desk, laying down on the smooth hardwood surface as his wings lay across the surface, his cock standing like a mage's spire off his belly now, fully erect.

Bade saw between his legs that Twilight was staring at that particular sign of male virility as he now lay on his back with his forehooves folded at his chest, his back legs spread-eagle on the desk and leaving nothing to the imagination.

"Wow...big." Bade thought he heard Twilight whisper, seeing her tilting her head to get more angles. His cock looked almost identical in shape compared to a pony stallion's—rather long and cylindrical with a thick medial ring in its center and an even thicker flare at its tip—his whole shaft black-skinned with only small flecks of pink flesh to match his pure-black balls. The only notable differences were the sheer girth of it and his balls being so huge.

"So, uh..." Bade said, red still burning on his cheeks as she looked at his penis like...well, like a mare in heat looking at a stallion's cock.

"Oh, right..." Twilight said in a distracted tone, blushing a bit and shaking her head as she realized where she'd been staring, not to mention the sudden increase in the fire in her loins, "Right...is this full length?" Bade gave a soft, subconscious glare, "N-no, I didn't mean it like that! It's just, for the study, I need it to be at full...erection...for accurate records.

"I, uh, I think so?" Bade said, unsure himself if he was at full mast, honestly not sure about much of anything at this point except that his foalhood crush, an alicorn princess, was staring at his penis and balls!

"Well, I wouldn't want the recordings to be inaccurate..." Twilight said, before suddenly sitting down and grabbing his penis between both hooves, softly starting to rub. It felt warm and firm, hard but spongy, slightly giving to her gentle squeezes but not bending completely. Twilight had never touched a stallion's penis before, so this was all completely new to her.

"T-Twilight?!" Bade asked in surprise, sensations of pleasure rolling through him as Twilight continued to rub softly, unsteadily...as though this was her first time doing anything like this.

"It's OK Bade, I'm just assuring full erection..." Twilight said nonchalantly, as if jacking off stallions was simply a part of every medical study.

"I...guh...I think that's...mmph...'bout as hard as it's gonna geeeeeeet..." Bade moaned out, before finding that Twilight stopped rubbing with her hooves...and instead he watched, then felt, as she lowered her muzzle to his cock.

Bade thought, in a minor state of shock.

She did.

Bade moaned against his will as Twilight licked his glans softly, his hips shifting up on reflex to the soft, warm tongue dragging on his member, a much stronger surge of pleasure going through him than with just her hooves.

"J-just ensuring full erection..." Twilight assured, though that excuse seemed to be wearing thin, as enjoying a stallion's pre-cum wasn't part of a scientific study! Each little dollop Bade produced, each drop his stallionhood drooled out for her, Twilight's tongue was quick to lick it up, her mouth moving as though she were savoring it...and secretly, she was. The raw, hormonal flavor of stallion set her senses and breeding instincts alight and made her tail start to involuntarily flag over her back, her clit starting a slow pattern of winking as she softly licked his flare like a lollipop.

It wasn't long before Twilight had started subconsciously moaning while licking Bade – her hips rocking back and forth as though she were being bred, her back arching up to a stallion who wasn't there – before she realized just what she was doing and stopped, blushing heavily and dropping her tail back between her legs. "I...uh...I think you're fully erect now." Twilight said, still blushing deeply, summoning the tape measure to her again. "Subject Bade's penis is fourteen-point-five inches long and eight in circumference, long and thick even for a thestral according to my studies, and for reference the average pony stallion is about eight to ten inches long and around five to six on average..." Twilight said, with more longing in her voice than she realized as she moved the tape to his sack, softly grasping both testes in her magic and gently wrapping the tape around them "...and each testicle is about four inches long and two inches in circumference. A very...virile specimen indeed."

Bade simply kept staring in his heat-pheromone-induced daze, before finally Twilight exhaled. "Bade, I have something I need to tell you. I didn't ask you..." she started, only to be interrupted.

"...in here to do a study, and intentionally redirected me to 'guard' you here so you could seduce me?" Bade finished, the red on Twilight's face growing a few shades.

"I-If you knew, why didn't you say something?!" Twilight asked sharply, flustered.

"Because we all have our coping methods Twilight. Mine is avoidance, and apparently yours is...studying to understand it more." Bade responded, Twilight nodding slightly, "I wanted you to be comfortable before admitting that to me....and I think you are now.

Twilight huffed, offering a soft nod. "Well, since all pretenses are off now and you know my true intentions...is this OK with you Bade? Being sexual with me, that is..." Twilight asked like a schoolfilly asking her school crush out on a first date, "I think I'm past needing studying as a crutch now, as you can probably smell."

Twilight's scent had grown stronger and she'd started dripping her mare-honey onto the floor, her tail flagged high and her arousal at a new peak. Bade's nostrils were flared as his cock remained at full hardness, starting to hurt a little as he smelled the fertile mare in front of him basically begging him to breed her, himself needing relief as much as she did now.

"I'm OK with this, as I...kind of like you too...but you do know that thestrals can get pony mares pregnant, right? I don't have any condoms." Bade's own cheeks flushed a little deeper, "Plus this would...kinda be my first time."

Twilight nodded. She had indeed learned that thestrals can crossbreed with ponies of all tribes and even zebras in her reading, and if anypony were to have vaginal intercourse with them in estrus, they would have to take the standard contraceptive precautions that they would with any other pony race, lest they likely become pregnant by them.

If the pony mare were to become pregnant by a thestral stallion however, or similarly a thestral mare pregnant by a pony stallion, the resulting offspring – or one of the multiple that could be born, given the much more common likelyhood of twins or even triplets among thestrals and their mates – would often be of the pony mother's or father's race, or presumably their original race in the case of alicorns. As for traits, it was very possible for the foal to have traits of the thestral parent – tufted ears, slitted pupils, bat wings, or fangs – or on extremely rare occurrence, be born a full thestral. If two thestrals breed, they would simply have another bat-pony pup or two.

"Yeah I studied on that, and don't worry about being a virgin. It's...my first time too." Twilight responded, before lighting her horn. She felt an even hotter burning in her belly for a moment, before ending the spell, "There, I used an anti-foal spell. Now I can't get pregnant for today as all sperm approaching my egg will be destroyed when trying to reach it." Twilight said simply, her tail once more starting to swish her fertile scent, permeating the room with her desire, "...but before all that, I should finish what I started. After all, everypony's first time should be special."

Before Bade could ask what she meant, Twilight quickly licked the underside of his cock from the base until she reached his flare, before once more taking its entirety into her mouth, earning a deeply pleasured moan from Bade and saturating her senses with male again. Encouraged by his moans, Twilight didn't stop sinking lower this time until her lips kissed his medial ring and his flare neared the back of her throat. As she pulled back, Bade's cock throbbed again and deposited a squirt of pre directly on Twilight's tongue, the masculine flavor making her moan deeply and sink down again.

Bade was meanwhile at a loss for words at this moment, the mare of his dreams going down on him, her fertile odor only driving him on as his hips started rocking on reflex to the hot, wet mouth on his upper shaft, hooves wrapped around his lower and pumping in tandem with her muzzle's bobs. Twilight seemed more than alright with his humping, not stopping him as she kept blowing him.

It was a surprisingly short amount of time before Bade felt a tickling in his balls joining the tightness in the back of his pelvis, the throbs in his cock telling him just how close he was, the sensual overload of the situation – he was getting a blowjob from a princess for bucks sake! – making him start to flare already. "T-Twilight, I'm...I'm close." Bade warned, but instead of pulling off at his warning, Twilight only seemed to speed up her motions.

Upon learning he was close and feeling his flare swelling in her muzzle, Twilight bobbed harder, swirling her tongue within Bade's glans process and hearing him gave a strangled sound as she did that, rewarded with another glob of pre on her tongue. Twilight felt like she was drunk or in a dream as she kept suckling his swelling flare before going down on him again, before finally, it was too much for the stallion.

Twilight felt her jaw stretching open more as Bade steamrolled over his limit, his cock going stiffer and flare fully swelling in her mouth before a sudden deluge of his thick bat-pony cum gushed into her muzzle, flooding her mouth with the bitter-sweet flavor of virile male. She kept pumping her hooves and bobbing on him as she gulped down his rapid shots of thick foal-cream, encouraging even more from him – and his body only too gladly delivered. So much so that Twilight missed a swallow and it instead came out the sides of her mouth, matting his crotch and her muzzle in his seed.

Bade meanwhile felt pure bliss roll through him with each shot of sperm-rich fluid that Twilight milked out of him, utterly speechless as each very hard ejaculation nearly stung his urethra, his body clearly mistaking her mouth for her fertile marehood and doing its best to impregnate this mare.

Finally, after nearly a half-minute of near-constant cumming, Bade's stream finally slowed, leaving Twilight's stomach feeling rather happily full of virile spunk and the stallion completely drained for the moment. Bade meanwhile heard the scratching of quill on parchment as she swished one of his final, thinner shots in her mouth, savoring it before swallowing.

"Wow, you thestrals stallions really ARE highly virile, aren't you?" Twilight asked, apparently scratching down notes, "That was at least one-hundred-eighty to two-hundred-fourty CCs of ejaculate! That's twice to twice and a half as much as pony stallions!"

Bade felt some pride at that – and before he knew it, after only a minute's rest, he was erect again.

"WOW, I knew the books said you thestrals got erect again fast, but within a couple minutes of such a massive initial ejaculation? Wow..." Twilight said, truly astonished. She had also learned that both male and female thestrals are very prolific breeders and had extremely high sex drives, usually spending the mare's entire estrus mating to assure pregnancy, with their estrus cycles usually being very short given how often, and with how much, she was inseminated during it. She'd also learned that the stallion thestral's 'outputs' are very large and virile as well, having at least fifteen billion sperm per ejaculation on average compared to a pony stallion's seven to ten billion, as well as a much larger, stickier seminal volume to boot. , Twilight thought with a blush.

"Well, you are a very beautiful mare in heat Twilight. That would give any stallion...inspiration." Bade said, Twilight blushing at the flirting even after what she'd just done.

"Well, you're not too bad looking yourself..." Twilight said, nuzzling against his cheek even as her innards burned with the power of Celestia's sun to match the blush on her cheeks, her instincts telling her to turn and present to this stallion already, "Bade, would you be willing to go... all the way with me?"

"Do you mean..."

"Mounting me, followed by sexual intercourse and ending with an internal insemination."

"...oh."

"Too scientific?"

"...and you still made it sound sexy."

"You can say no if...you want to. This...isn't a command."

"Of course I could my princess, but I want to do this for you."

"Thank you Bade..." Twilight said as she turned to him with both wings opened as she stood before a bookshelf, levitating a quill, scroll, and book titled 'Studies on Thestral Mating Habits' as she flagged her tail to him, showing everything under her tail to him teasingly whilst giving him the most sensual of looks.**

After that was all sorted, her materials gathered and her stallion seduced fully, Twilight mounted the desk, her flank high in the air and her tail over her back, legs spread as she presented herself to the horny stallion. Bade sniffed her fertile slit then gave a breeding whinny, that instinctive mating call making a thrill go up and down her spine, her clit winking rapidly in response and turning Bade on even more. In response to her body's welcome, Bade mounted her on the desk, his hooves making two hard thuds beside Twilight, feeling his cock throbbing underneath her belly and between her teats. Her whole body was warm, very warm, under his sexually-sensitive chest, her raised body heat undoubtedly a result of her estrus.

"Bade, please... I need you inside me so badly..." Twilight moaned out like the mare in heat she was, earning another throb from Bade's cock at the lascivious tone she was using, her whole being wanting that cock pounding her into the ground right now, "You have my permission, just...start gently please. I've never been penetrated."

Bade nodded, once more remembering Twilight was a virgin and all that entailed. Slowly he shifted his hooves until he was in position, Twilight helping as well as she could, and started humping against her with the thrusts of an inexperienced stallion. Each time he humped, he'd miss, both getting more and more antsy with each miss.

"Oh for..." Twilight groaned out, grabbing Bade's cock in her magic after the eighth miss and moving it to her winking, drooling marehood.

Given how simply worked up she was, with little squirts of her lube even coming out with each wink, Bade realized she had it bad. On instinct Bade reached up and softly bit her ear, an instinctive way of a stallion telling the mare he had mounted to stay put.

Twilight moaned at the pressure on her ear telling her to stay put and be bred by this stallion, gladly obeying and feeling Bade hit her entrance on another wink, and that sent some pain through her.

"Do it." Twilight commanded instantly, and Bade obeyed. In a second, Twilight's virgin canal parted, making her give only a quiet whimper of discomfort before the stretching feeling was overwhelmed by the sensation and pleasure of being filled up in her heat, Bade's medial ring spreading her just that much more and sending a surge of sensations through her.

"N-no, d-don't stop!" Twilight exclaimed as she felt Bade slow in reaction to her whimper, quickly feeling him sliding deeper and deeper instead until he bottomed out in her. His flare ended up very firmly pressed to her relaxed cervix, her whole passage wonderfully filled and stretched by him. Twilight felt Bade tugging her ear gently at the same time he bottomed out, her groaning especially loudly at that.

Bade's whole cock was inside her.

Bade was breeding her.

She was being filled in the way her instincts demanded, and he provided, "N-never stop, I need you..."

"I w-won't stop." Bade promised, his gentle, unsteady thrusts starting as her hips rocked with his rhythm, inviting him as deeply into her as she could.

Just as she was about to question why he wasn't rutting her silly yet, she felt him pull out then push against her lips again, sliding inside very easily given the amount of her natural lube virtually gushing out of her marehood now, coating his cock well in her lust.

As her entrance spread nicely already, more of his thick length filling her up again by the second, possible consequences could be damned even if she wasn't protected. He was cumming in her. "YEEEeeeesssss!" Twilight hissed out in pure pleasure as he slid deeper and deeper into her slick, silken love-tunnel, her body squeezing him tightly in greeting.

Her entrance winked all over him, giving kisses along every inch he gave her, her body gladly accepting them and stretching so wonderfully to accommodate its first guest again. It hurt just a little to be stretched so suddenly like that, but no worse than stretching out a cramp.

"Oh-my-gosh-you're-so-hot-and-tight!" Bade moaned out, feeling like his cock was trapped in a vice made of wet silk that was set on fire, even still sliding into her very, very warm passage easily.

"H-harder..." Twilight instantly demanded, and Bade did as he was asked, taking her ear in his mouth and biting down again softly, making Twilight feel another surge of pleasure roll down her spine as he humped into her more.

"S-since you're safe, I w-won't even pull out if you don't want me to."

As Twilight felt him continue, she gave a breathy 'don't stop' in response, before feeling him sliding back into her fully, filling her so perfectly once more. As he stopped gripping her ear in his mouth, she was slightly disappointed, but her inner fires were stoked even higher by the promise that he wouldn't pull out. "P-Please, I need you to f-fill me up!" she begged, fully running on instinct, her back legs trembling in need. She let out a desperate moan as she gripped him tightly inside her every time him tried to pull out, her body not wanting its partner to leave it for even a moment; wanting Bade to cum in her, to seed her and get her pregnant.

"Twilight...I promise I will...you feel...so good...I think I l-love you..."Bade whispered out between thrusts, the wet claps of his swollen balls on Twilight's soaked butt sounding throughout the study, accompanied by her moans.

As his thrusts increased moments later, Twilight was long gone, drooling both from her open, panting mouth and pussy alike as she was being bred the way her body so needed, her pussy being massaged by a stallion's bare cock the way nature always intended. "M-Mate me, inseminate me!" she demanded, her body running purely on her base desire to reproduce; to feel this stallion's virile totem planting its seed in her and making a foal grow in her womb. Then she realized what he'd just said; that he loved her. That just made her want him to take her even harder. "W-we can worry about everything else later! I-I just need you TO BREED ME NOW!"

Bade felt himself getting close at Twilight's enthusiasm and the perfect squeezing her passage gave him, his instincts screaming at him to do as she asked and breed her; even though he knew it was futile, his instincts surely didn't. All he knew was that he was humping into an in-heat mare, his cock deep inside her hot, squeezing, fertile passage, and he had permission to cum in her.

"I'm...I'm close..." Bade said, feeling that tell-tale pressure building in his pelvis again, humping a bit harder as Twilight constantly squeezed and winked around him.

As Bade said he was close, confirmed by the intense throbbing of that thickness spreading her heat-swollen walls – that deep, instinctively-telling growing at his tip swelling to plug her up and keep his virile cum as far in her as possible – Twilight felt herself winking constantly as little spurts of her fluids were squirting out in anticipation, her whole body tensing up and her inner muscles milking him of his load; Twilight's only desire in the world at that moment being to get knocked up. "P-please, oh by the goddess PLEASE cum in me..." Twilight moaned out, desperately needing relief, her whole body and instincts screaming at her to make this stallion cum in her.

At that final encouragement Bade could take no more, hilting his fully-flared cock into her and feeling her deepest wall surround his glans, its process surrounding and pressing against her cervix as he pulsed even harder and more frequently; poised to spray his cum directly into her womb.

Twilight virtually exploded and imploded at the same time as she felt those harder-than-before throbs from his cock deep inside of her, feeling his rock-hard cock pulsing along her whole, well-spread passage while his flare was firmly pressed against what must have been her cervix. As he rammed himself home that last time, the tip of his member spread her deepest barrier just a bit more.

Twilight let out a sheer, primal whinny at that feeling, cumming so hard it felt as though her body was trying to suck his whole body into her, her mind awash with pure, hormonal bliss and relief. Twilight's back legs quivered unsteadily as her whole body tensed, her pussy rhythmically milking him.

"Twilight, I can't hold it anymore!" Bade exclaimed, feeling her foal-passage milking him of his seed.

"C-CUM IN ME!"

...then it happened.

Twilight let out another, more forceful whinny at that hot, wet, deeply-satisfying impact of thick fluid deep inside her belly, likely her very womb, her body knowing exactly what it was and eagerly working to milk out every drop of seed that the stallion cumming inside of her had to offer; milking his could-have-been foal into her womb. Bade's orgasm seemed to keep going forever just like it had in her mouth, her body wracked with orgasm after orgasm as she never seemed to stop cumming the same as him, her fluids streaming down her trembling rear legs and spraying his balls and thighs with each frequent climax she hit.

Bade felt Twilight's pussy ripple along his cock as he came harder than ever before, painting her insides thickly with his foal-cream, coating them in that life-giving liquid. He felt as if he'd never stop pulsing his cum into her, gripping her as tightly as he could, hilted as her body tried to claim his foal.

When all was said and done nearly a minute later, with Bade still hilted and flared deeply inside of Twilight, her belly feeling utterly and contentedly filled with virile stallion spunk, Twilight in turn was holding him very tightly inside herself. Twilight's heat was dead and drowned as she simply stood there and panted, recovering from the most intense, satisfying in-heat orgasm she'd experienced to date, her pussy still seemingly kneading him even after she'd come off her high and he'd stopped pumping into her. Both of their fluids were now streaming down her legs as there simply wasn't room for one more drop inside of her, forcing any more out.

"Holy hay Twilight..." Bade gasped out as he remained mounted on her and hilted to her now-filled core, recovering as he felt her insides still kneading his cock for seed.

Twilight sighed happily, her mind clear for the first time that day, and she found herself smiling, beaming really, at that utterly relieved and soothed sensation in her lower belly; as though somepony put aloe vera cream on a bad burn deep inside of her.

Bade dismounted her as her inner muscles finally relented and allowed his softening cock to slide out of her with a schlick, a stream of his cum oozing out of her and onto the floor.

Twilight collapsed onto the desk the moment he pulled out, so utterly satisfied at the moment even if she still felt that slight burn in her now-cum-stuffed belly, knowing it'd keep up until her estrus ended or she was finally pregnant. Given how much virile cum was stuffed in her, she very likely would have conceived within the day no doubt, provided she didn't have that nifty little spell to prevent it. As such, her heat likely wouldn't end until its normal time...not that that was a bad thing anymore, with a willing stallion to help soothe it.

"Twilight, that was...amazing." Bade said, though that felt like the understatement of the century, "I only wish I could have pleased you longer."

"Don't give me that! You did great for your first time! Besides, I came too...more than once. All I can say is I'm glad I put that spell on myself. With how much you ejaculated inside me, I'd be pregnant by day's end without it!" Twilight said, before nuzzling into his neck. "Also, Bade, I think I may love you too..."

As he thought about what they'd just done, now able to given neither were under the fog of lust, and about what she'd just said, he reached down and kissed her on the lips.

Twilight gave a quiet whinny of surprise, but pushed back into the kiss, wondering why she hadn't kissed him before they'd rutted. It was a simple kiss – chaste, inexperienced – but even still it conveyed what words simply couldn't; how grateful they were to each other for what they'd just shared, and the feelings they held even after all these years apart.

After kissing for a brief while, cuddling close, Twilight soon felt a hardness pressing into her again.

"You're hard again, aren't you?"

"Sorry?"

"Don't be sorry! Put it in me again, and that's a command!"

"Yes ma'am!"

~

Outside the study door, a certain bat-pony mare masturbated furiously with one of her oversized toys while watching through the keyhole, watching as her two superiors screwed each other senseless and leaving a massive wet-spot on the floor as she came once again, struggling to stay quiet through her throes of yet another orgasm.

~

After another few orgasms from Twilight and another heavy load from Bade, they lay on the study floor, cuddling with each other after such physical exertion. They kissed softly before giving the other a smile, then both fell asleep in the other's embrace; uncertain what the future may hold for them but knowing it would definitely involve more of this.

Author's Note

* - This is meant to be the ponification of 'hands' as a measurement, with a 'hand' being used to measure horses and being equal to about four imperial inches. Bade is about 4' in height, or 132cm and ~454kg, rounding up, in weight. quite a big boy.

** - since I can't link directly to images, allow me to include a related NSFW picture to copy/paste to your browser! https://derpibooru.org/ 1255856