//-------------------------------------------------------//
A study into the viability of homo sapien/equine reproducibility
                         -by TAW-                          
//-------------------------------------------------------//
//-------------------------------------------------------//
                         Chapter 1                         
//-------------------------------------------------------//
Chapter 1
A study into the viability of homo sapien/equine reproducibility.
"Now, I'm sure you're both wondering why I've called you here today." Twilight Sparkle announced, sitting back in her chair as you and Applejack stood before her in one of Applejack's more remote barns. You'd received a letter earlier that day inviting you to An experiment built for 3, signed with Twilight Sparkle's cutie mark. It gave no further information - save for a date, time, and place - and your curiosity had spiked, leading you to be at the place, on the correct date, at the allotted time.
Applejack had already been there, scratching her head outside of the barn and giving the door a fruitless buck. It was stuck fast, and she had been getting somewhat frustrated until it suddenly opened all by itself and Twilight herself invited you in, closing the door behind you and plunging the barn into total darkness. A moment later, a floating orb near the top of the barn sprung into life and filled the whole room with an eerie glow.
"Uh, sure am Twi, what're ya'll dragging us both out here for?" Applejack asked, the irritation clear in her voice. She probably had apples to buck or something.
"Science!" Twilight exclaimed, clapping her hooves together and jumping out of her chair.
"Sci... ence? Twilight, you know I ain't no acade... scient... genius! I can't do science!" Applejack whinnied, scraping her hoof against the hay-strewn floor of the barn. The walls were lined with old bales of hay that had either been rejected by quality control (Granny Smith) or just forgotten about, and the whole place had a strange musk, like nobody had been in it for months, and nobody else would be in it for months afterwards.
"No, you're my test subject, Applejack! I know you can buck, and that's what I need you to do!" Twilight exclaimed, walking towards you while talking. The moment she got within a few feet of you, she broke into a quick dash and opened her mouth as she dived for your crotch.
Woah, there! Luckily she was only a little pony, and you could stop her dive with a single hand, easily keeping at arm's reach. What in Equestria did she think she was doing?
"Science!" she pouted.
Didn't look like science to you.
"Do you want to see my notes?" she grinned, pulling them out of the saddlebag she'd left across the room and bringing them over to you.
An experiment to prove the viability of Human/Pony interspecies relations,  
By Twilight Sparkle
This study intends to prove once and for all whether the mythological creature "Human" is capable of procreating with standard equines using regular means. This experiment will require multiple trials on as many test subjects as possible, and must be conducted with the utmost scientific rigour.
As I cannot trust anybody else, I, Twilight Sparkle, shall be the control dataset. I may be able to convince my friends to form other datapoints, as all information collected will be invaluable in drawing a conclusion.
While standard biology suggests such reproduction should be impossible, this has never been proven[...]
Wat.
"Ugh, you humans are so dense," Twilight complained. "It's very important we find out whether pony women can be impregnated by human men. That's why you're here. Take off those pants."
"Woah there, Twilight! You ain't asking me to...?" Applejack stammered, bowled over that her awkward, bookwormish friend was suggesting this.
"Of course not, Applejack. I shall be the control group, all you have to do is help me get him ready." she explained, pointing to the seventeen pages of notes on how exactly the experiment should be carried out. A quick glance showed you that not all of those steps were entirely necessary. For one,
Rarity possibilities:  
May enjoy having flank slapped and being called a bad pony -- must investigate further.
Didn't seen rigorously scientific to you, but you were no scientist. What did you get out of this experiment, anyway?
Both mares stared at you.
"Ya'll ain't kept your eyes off my flank since the day you got here, don't go pretending ya'll're prudish now!" Applejack snapped.
"And you'll be contributing to science! Oh, I'll be able to publish this, you could even have your name in the acknowledgements! And, of course, I'll have to put you through a wide variety of test ponies before I can be sure. I've already sent invites out to the rest of my friends, some of the townsponies, Celestia and Luna, some of the Wonderbolts, oh, basically everypony I could think of. Not today though, this is just the first run." Twilight explained, before pulling out a long scroll containing all the ponies she'd invited and on what day. You had a similar list, though it was a mental one - it was the list of ponies you'd had your eye on since you got here. Applejack had been right, she had a nice ass.
Applejack walked over to you and effortlessly pushed you to the floor, her incredibly strong legs easily overpowering you and throwing you onto a pile of hay, which thankfully cushioned your fall. Almost immediately, she began to fiddle with the button on your pants in her lips, struggling to open it as her brow furrowed and she began to grow frustrated.
"Excellent! You get started, Applejack, and I'll..." Twilight started, before trailing off, realising that she'd prepared everything that needed to be prepared. The magic orb above her was not just giving light, it was also recording everything, meaning she didn't even have to take notes until afterwards. Ideally, the experiment would go best if she simply got stuck in.
"Out of the way, Applejack, the experiment begins!" Twilight exclaimed, grabbing Applejack in a magic glow and lifting her off before kneeling down at using her own lips to try and undo the troublesome button.
"Uh, Twi? Why not just magic it open?"
Twilight spat the button out and stared at Applejack. "Ponies have done this without magic for thousands of years, I can't dirty the results! It's unfortunate, but he's simply going to have to run his hands all over my body with whatever intensity is required by the situation at hoof! Now come and help me with this button, I think if you grab that bit and I pull here we can get it off." Twilight responded. Her excuse was paper thin, and all three of you knew it.
Applejack trotted over and did as she was told, grabbing the edge of your pants in her teeth and pulling while Twilight pulled another piece and wiggled. Eventually, the button came unstuck and your pants opened up. The bulge in your underwear was quite noticeable, as was to be expected after a several-minute assault of two pony muzzles pressing and squeezing up against it.
Applejack and Twilight Sparkle briefly looked at each other before each grabbing one leg of your trousers and pulling, quickly flinging them away to land somewhere on the dirty floor. Separated from her goal now only by a thin sheet of material, Twilight knelt close and inspected the shivering tent protruding from your crotch.
"Note for later," she spoke into the air, "subject smells nice, though my personal biases may be shining through."
"Ya'll mean the way you're presenting like a schoolfilly, Twi?" Applejack snarked, looking at the way Twilight's rear end was facing into the air, and the way her tail faced away from her body at a right angle, raising to give anybody who cared to take a look full view of her most private parts.
"The scientific method lets us strip away our own biases and view the world untainted, Applejack!" Twilight said, while subconciously wiggling her rear and staring at the throbbing lump in front of her, completely fixated. "I'm perfectly capable of carrying this study out," she complained, "now can you please pull these off so I can watch it?"
Applejack rolled her eyes, there was no use arguing with Twilight about these things. It was the same every time, though this was the first time she'd expressed such a strong interest in this particular area. Applejack leant down, grabbed the side of your underwear in her mouth, and pulled, yanking it off of your member and down your legs, where it probably met a similar fate to your trousers - not that you were paying attention by that point.
The instant it was visible, Twilight Sparkle had pounced, immediately nuzzling the area where your shaft and balls met. The feeling of her hairs brushing against your oh-so-sensitive penis was mindblowing, and she knew it. Within moments, she let out an exploratory tongue, giving the area a tiny lick and the smallest taste. Her tongue was hot, wet, and willing, and she used it with gusto. Slowly, her licks grew both more frequent and more adventurous, lingering longer against your exposed skin.
"Twi, are you really just gonna-" Applejack started, before Twilight grabbed her around the neck with a magic grip and pulled her down until her nose was level with the top of your penis.
"Science, Applejack! It's fun, come on!" Twilight insisted with a grin. Applejack shrugged - if it'd make her happy, what else were friends for?
Applejack tended to enjoy subtlety and a slow warmup a little less than most ponies. Reaching forward, she quickly wrapped her tongue around the head of your shaft and pulled it down into her waiting mouth, letting Twilight concentrate on teasing and tickling the areas down below while she rolled it around in the hot, wet confines of her jaw. All too quickly, she began to slowly rock back and forth, running her tight lips over the tip of your cock and letting her hair flow down and tickle against your leg.
Twilight remained fairly content down below, taking her licks downwards to avoid Applejack's slowly moving chin, to meet your balls. Every so often, she switched tack, moving from licks to nuzzles, and from nuzzles to light sucks and kisses. Her forehooves found their way alongside her muzzle, cupping and rubbing against your balls and inner thighs whenever her face left room for it.
One forehoof did, anyway. The other slowly snaked its way along her chest and stomach, making its journey towards her almost embarrassingly wet slit. She claimed it was for science, but the quiet moans you heard from down below you as she began to slowly stroke herself insisted it was anything but.
In contrast to Twilight's slow, intimate sucks, Applejack was quickly moving on. Each time she shifted back and forth, she took a little more of your length into her mouth, slathering another few centimetres with her saliva. Every thrust was accompanied by another swirl of her tongue - nothing elegant, nothing practised or careful, just a strong scrape from side to side.
As she began to push you deeper inside of her, her eyes began to close as she concentrated on not gagging, letting her eager tongue and homely mouth do everything she needed. She let out tiny, low pitched groans as the very tip of your length began to brush against the top of her throat, reminding her that she really should slow down. She didn't.
Twilight was somewhat lost in her own little world, happily sucking away at the slightly hairy pair of balls while she ran her hoof around in unsteady circles, bringing herself to heights of pleasure while she did the same to you. Her moans were almost unabashed as every few seconds she let herself go, resting against your body and letting the air escape through her slightly parted mouth.
"Ow! Consarn it, Twi!" Applejack complained, rubbing her chin. That last thrust downwards had been met by one of Twilight's more enthusiastic licks upwards, and a spectacularly badly timed one, jabbing the end of Twilight's horn straight into Applejack's head. "Watch what you're doing with that thing!"
"Sorry, sorry!" Twilight apologised, after taking a moment to come to her senses and realise she was sprawled out across the dirty floor slowly pleasuring herself. "How about we swap?"
"Nah, let's just get on with this," Applejack responded, clearly growing bored with the slow speed they were taking. It wasn't really her style. "C'mon, you, don't leave the pretty purple lady waiting." she snarked, holding out a hoof to help you up.
Twilight blushed and muttered something about it being science. Both you and Applejack rolled your eyes. If it was anything, it was chemistry - you could smell chemistry, and you could smell this. You wiggled your finger in a circular pattern, asking her to turn around, something which she immediately complied with.
Chemistry? Try biology - Twilight's mind was clearly clouded with excitement and this clearly hadn't been an unbiased experiment since the start. No matter, you had science to do.
Taking a step towards her, you saw her noticeably quiver with excitement each step you took. When you lightly brushed your fingers against her rear, she quickly pulled away as if your very touch sent an electric shock through her body, before just as quickly returning, perhaps even pushing herself into you a little. Taking that as a good sign, you grasped more forcefully, resting your palms against the sides of her ass and drumming a little beat with your fingers. Each finger-fall resulted in a shiver, and the whole finger-song resulted in a happy moan down below, from where her head was resting against a small and hastily prepared pile of hay.
Her forelegs were bent, bracing her against the ground ready to absorb any impact you cared to place on her, and her hindlegs were straight, raising her rear up to the perfect height for you to insert yourself. She'd probably measured this.
Slowly, you drew a finger around her ass, tracing the edges of her cutie mark as she squeaked and cooed, enjoying your touch, but at the same time lusting for more. Her tail quivered with anticipation as your other hand continued its drum beat, slowly driving her wild as your teasing brought her closer and closer to breaking the "no magic" rule and taking you there and then.
"Oh, get on with it." Applejack moaned, sick of having nothing exciting to watch. You took her point.
Bringing your hands back to their starting positions, gripping both sides of her rear and holding her steady, you slowly aligned yourself, resting the head of your shaft against her slick, quivering marehood. Taking a breath to steel yourself, you pressed in, slowly penetrating the excited purple unicorn and driving her tiny gasps of anticipation to larger moans of much-wanted pleasure.
Slowly, you continued, pressing harder and feeling her tight walls close in around you. Her excitement was off of any scale she might have used to measure it, and each extra inch she took just pulled her further towards the edge. Pushing inside of her was like turning a tap, turning the slow but steady dripping of her aroused areas into a relative gush, easily lubricating your journey. Clutching harder with your hands, you pulled her towards you as you pushed in, wanting to be as deep inside of her as you could.
Too soon, you felt her gorgeous purple behind press into your legs, and you knew you were as deep as you could go. Every haggard breath she took shot through both of your bodies, every beat of her heart sent her quivering walls into overdrive, battering against your shaft for all they were worth. Every instant you were inside of her felt like an age of agonising pleasure.
And it wasn't enough.
She pulled back, rocking forward against her forehooves and pulling out just a little, before pushing back into you as hard as she could. She wanted more. She needed more.
Waiting a moment until Twilight was pulling away, you mirrored her, pulling back half your length before meeting her frantic thrust back in the middle with an audible squish. With your hands firmly grasping her rear, you could control how far apart you grew and ensure you were never too far outside of her, no matter how quickly the two of you thrusted together.
As both of you grew more forceful, each motion jerked Twilight's head around, pushing her harder into the hay as she grunted and groaned, rivers of pleasure running through her body. Each stroke sent a strike of bliss through her mind as her forelegs did their best to keep her stable despite the constant assault, and each thrust was accompanied by an unintended squeeze as your body, too, began to betray you and do as it wished, flexing your fingers and rubbing them against her coat, just wanting to feel her against you.
"Applejack!" Twilight gasped, eyes softly closed and mouth barely able to form words as each thrust robbed her of her concentration for a little while, letting her moan quietly into the ground and drool helplessly. "Kiss me!"
Applejack hadn't been stationary during the whole ordeal. As unshakable as she liked to think she was, she couldn't stand by and watch her friend get roughly rutted into a groaning, shivering pile of flesh without it triggering so many of her own feelings that she was barely able to think straight either. When the request came, she didn't question it.
Kneeling down in front of the relaxed purple body, Applejack lifted Twilight's head with a hoof and lowered her own head to meet it. Parting her lips, Applejack moved forward, meeting Twilight at the apex of a thrust and letting her grown happily deep into Applejack's throat. Twilight was far too distracted to really put any effort into it, but Applejack was happy to do her bit, gladly leading with her own tongue and letting Twilight's simply follow in the throes of ecstasy.
Applejack closed her eyes, letting herself daydream off into fantasies while her mouth gleefully met Twilight's, and her ears were happily hearing a chorus of moans and grunts from the other two parties. Something about being so close to her normally so reserved and practical friend as she lost herself in her own feelings and sensations felt so very right. Something about watching from the sidelines, only somewhat taking part as one of her best friends was mercilessly screwed seemed to set her coat on fire - all concentrated around one bit in particular.
Twilight's groans grew stronger as the pleasure finally began to wash over her, overwhelming every last thought she might still have had as her forelegs gave in an instant before every muscle in her body spasmed and quivered, and her voice rang out through the abandoned barn as she fell into the ravine of orgasm, temporarily losing her mind as her body completely took over.
Her experiment was a success. The clenching, quivering, squeezing and shifting of her tight hole drove you over what little resistance you still had, and you joined her in orgasmic freefall. Shot after shot of scientifically approved semen shot deep within her body as you clutched roughly at her, pushing yourself as far in as you could go while she did the same from the other end, pushing your bodies together so hard it almost hurt.
Finally, she collapsed, your length slipping out of her as she fell to the side into the hay, happily mumbling and groaning as her eyelids struggled to open, before finally sliding closed as she decided that maybe a little rest wasn't so bad.
You and Applejack looked at her. Her face was splattered with two ponies' saliva, and her rear was dripping with two creatures' juices. She looked so happy, lying on her side with a soft smile on her face, breathing deeply and apparently already asleep. She looked so peaceful, you couldn't think of anything better than to lie down beside her, wrap your arms around her soft, squishy body, and join her in slumber.
Applejack could. Taking your receding member into her mouth, she began to massage it with her tongue, letting her saliva wash over it and her tongue clean away all the juices and dirt from the freshly fucked Sparkle's earlier fun. When it was finally long enough she couldn't hold it all in her mouth any more, she pulled back, letting a few strands of saliva bridge the gap between the end of your cock and the start of her mouth.
"Ya'll done think you're done, do you? C'mon, do me next, sugarcube." Applejack demanded, turning around of her own accord and wiggling her rump.
Twilight stirred, quietly muttering "No, Applejack, not in there! You'll mess up the results!"
Applejack paused, raising a hoof to her mouth in thought for a moment. "Oh, I know! How about ya'll take the other one, just this once, y'hear?" she offered, raising her tail another few inches to reveal the puckered hole above your original target.
Twilight moaned happily and nodded against the ground, though neither of you could be sure whether that was approval, or just her still loitering in post-coital bliss. Nor, in fact, did either of you care.
"None of this slow stuff, either, partner. Take me hard." Applejack instructed, ensuring that this second experiment would be performed to her specifications.
Gripping her ass as hard as you could, you pulled her around and pushed her into the nearest bale of hay. Before she could recover her footing, you had your hands on her rear once more, delivering a well-intentioned but still rather hard and very loud slap. Applejack whinnied, her tail flicking around as the pain of your strike somehow translated into a perverse pleasure.
Using your spare hand, you quickly realigned yourself, pushing your already lubricated shaft against her tightly puckered hole. You heard a gasp from within the now horribly misshapen hay bale, and knew that you were doing the right thing.
You thrust forward. Foreplay be damned, she'd just watched her friend get laid, she was ready. She grunted in a mixture of pain and surprise as you pushed past her contracted sphincter in one smooth thrust, the mix of saliva and Twilight's juices making for a relatively easy journey. A few seconds later, you hilted yourself, all that excess momentum going into pushing Applejack's head harder into the hay, muffling her groan as your shaft rubbed in all the right places.
Her anus was unbelievably tight. When she squeezed down, it felt like a vice grip strangling your cock, so hard it could barely move even with the lubrication, and even when she didn't each centimetre was still an effort all on its own. An effort well worth it, though, every motion sent a wave of pleasure shooting through you. Every motion apparently pleased Applejack quite a lot, too - though her head was quite firmly entrenched in hay, her moans escaped regardless, muffled but unstoppable.
It was harder to find a rhythm when each movement took serious effort, but you tried your best, thrusting in and out as quickly as you could manage without the pleasure overwhelming you. Applejack did her best to meet your thrusts, rocking back and forth on her hind legs, but it still didn't seem to be enough for her. Her grunts were sporadic, and didn't seem to be rising in volume very quickly. Her tail swished around, brushing against your chest and generally getting in the way.
You could use that. You wrapped it around your hand a few times, and gave it a tug. Applejack's whinny-moan cut through the hay like it wasn't even there, and you knew you'd found your secret weapon. Tugging on her tail like it was some perverse bridle used for an entirely different kind of riding, you drove Applejack closer and closer to her edge, brutally slamming into her again and again with all the force you could muster.
Though you'd only just came mere minutes before, your body was quick to recover and meet its new demands, and you quickly felt the rising tide of tingly pleasure begin to concentrate around your crotch once more. You were close, she was close, and the world felt like only this room really mattered.
Almost doubling over as the sensations began to overwhelm you, you did your best to continue your strokes even though all your body really wanted to do was push in as hard as it could, and release everything it had. Mere moments later, your last defences gave up, and that's exactly what you did.
Applejack moaned happily as the sensation of your hot load spreading around inside of her finally drove her over the edge, and the boiling heat from her rear met with the burning passion in her mind to create a roaring, devastating orgasm, and her body collapsed, resting against the hay bale as her mind began to shut down.
You stumbled back, admiring the view. The first few drops of your seed were even now starting to leak from Applejack's behind, her body still mostly suspended by the hay as her happy moans and groans permeated the room. Behind you, Twilight Sparkle still lay happily basking in the aftermath of a good rutting, though she'd already regained most of her conciousness, and could probably have struggled to her hooves had she had any reason to.
"Hey," she whispered a few times until she caught your attention. "Hey, over here." she offered, spreading all 4 legs in the universally recognised symbol for "I want a hug." Not something you would ever deny.
So, what happens if her experiment proves that humans and ponies CAN reproduce, anyway?
"Oh, don't worry about that," Twilight whispered into your ear while she wrapped her legs around you and hugged tight, contentedly nuzzling into your neck, "I'm still only halfway through my cycle, I won't be in heat for months yet."
So, the whole experiment was pointless?
"I wouldn't say pointless, would you?" she asked, with a weak but very sly grin.
So the experiment was a sham. You thought you'd all learned something from it anyway.