Hands-On Sample Collection

© 2025 by Kaydrien

“Is that even legal?”

Sherri grinned down at her human coworker. It had to be down, of course; Sherri’s horse half added at least three feet of height. “Probably. Who care?”

“We should just use the tranqs and the stim probe.” Wendy tried. “That’s what they’re for.”

“Tranqs aren’t good for them anyway. Besides, it’ll be fun.” Sherri waved off the concern with a flick of her hand.

“If that’s what you want, I guess.”

“Oh, definitely.” The centaur lifted her binoculars to her eyes. “Just look at that guy!”

Wendy hoisted her own binoculars, having to lift aside her auburn bangs one after the other to make it work. She had to track over the horizon a bit, past a number of wild mares and foals, to find the stallion.

“…Probably about sixteen hands tall…” She thought out loud, feeling as if some response was expected of her and defaulting to a professional summary from bafflement. “…Dapple gray but unusual color pattern, brightens at the chest and forelegs instead of darkening. Distinctive white streak running up from the left gaskin…. Moving well…”

“Dreamy~” Sherri summarized.

“I guess.”

“I bet he’s totally packing, too.”

Wendy flushed at her friend’s frankness.

“I… guess that’s possible. Can’t really tell with the tall grass. In the way. And not being everted.” A breeze stirred the grass, granting the human an undeniable glimpse of heavy black scrotum between the hind legs. “Definitely a stallion, though.”

The centaur beside her hummed a distracted agreement. She lifted the loop securing the binoculars around her neck and tossed it into the back of the flatbed truck the two women used for field work. It bounced gently on the cushion that served as Sherri’s car seat. “Imma go tap that. Be right back.”

“Hey, wait-“

Sherri didn’t wait, barely tossing back a wave and a grin as she cantered away from the flustered human, tail flicking upward.

Wendy grumbled halfheartedly, though she didn’t really have anything else to say. Certainly nothing that would change Sherri’s mind. Instead she climbed up into the back of their pickup and settled herself on Sherri’s seat. She should probably at least keep an eye on her friend in case something went wrong.

Sherri, untroubled by any such concerns, made good time on her long legs. She slowed to a trot and then a walk as she approached the hunky stallion and his herd. Some of his mares shuffled away from her, a little wary of the sudden newcomer but not overly frightened by her strange shape.

The stallion instead trotted over toward her, the hefty animal barreling toward the source of his herd’s unease, ready to defend against any sort of danger. He slowed to a halt within around thirty yards.

“Heyyy there, handsome.” Sherri greeted him with her voice low and encouraging. “Come here often?”

Confused, the gorgeous male sniffed at the air, turned his head this way and that to get a good look at her. The stranger wasn’t a predator, but instead seemed a very strange horse of some sort. And making weird noises at him.

“God, you are sexy.”

The male hesitantly circled around her. The weird horse wasn’t a stallion, which was good. Drawn by an upward flick of her tail he approached a little closer, coming up beside her and sniffing inquisitively.

Sherri generously swung her back end in his direction while she enjoyed the view herself. Definite stud material, muscular, not too lean. And his coat was smooth as hell for never having seen a brush. The sight made her tail flick harder, spine muscles straining to expose herself as much as possible. “Come onnnn… take a good look. I’m here for you, big boy.”

The words were pointless, but the motions got the point into his feral brain. There was a female here. And she was interested. Shuffling heavily forward so as not to spook her (and unaware that the delicacy was thoroughly unnecessary), he snuffed at her hindquarters, instinctively seeking olfactory confirmation that she was in heat and ready.

He didn’t find quite what he was accustomed to from the mares of his herd. Sherri didn’t have the same degree of heavy heat pheromones they did at estrus, had a lighter scent in general as a civilized being that bathed regularly. Nonetheless there was arousal there. Penis dropping from his sheath he nuzzled at the strange mare’s backside, licking at her genital folds.

“Hooooo.” Sherri exclaimed appreciatively, upper body twisting to catch a look between the legs of the stallion. He was at enough of an angle to her lower body to allow her a fairly decent view of the sizeable meat as it firmed up. “I was right, you’re carrying a log down there. Gotta be like two feet.”

Though Sherri’s body was only giving some of the signals the stallion was used to, she also wasn’t kicking him away or moving out of his reach. As a hot-blooded stud he happily decided that was enough. Withdrawing from licking at the winking and leaking vulva he reared up, dropping his barrel on the centaur mare’s back. The weight forced a huffing but appreciative breath out of the centaur.

She was a fair bit smaller than him, thirteen hands tall at the horse-half shoulder to his sixteen. His forelegs sandwiched her barrel as he clambered atop her. Six hundred-odd pounds of his weight settled onto her haunches. An oppressive, masculine weight that sent a drizzle of her juices down the inside of her legs and over the equine breasts she carried between them.

The head of the stallion’s penis rammed into those teats, bouncing roughly off a nipple and collecting some of her slick on its surface in the process, then jabbing around upward. Sherri paused any verbal flirtations to moan and shudder incoherent vocalizations, devoting her attention to the sensations from behind. Hot body atop and around, legs pulling her sides, questing tip prodding around her nethers. Sherri was in heaven, hands groping at her breasts through the cute button-top she wore for field work to spice things just so.

It took a bit of blind jousting but eventually the cocktip hit just so as her pussy was on the loose side of a wink, sinking in to the wet welcome. Entrance achieved, the stallion shimmied himself forward and inward, spreading her silky walls around him. The geometry of the equine sex organs rubbed her passage tightest over the rim of the blunt feral cockhead, a ring of pleasurable fire formed by the friction of that hardest point of contact. Thighs tightened convulsively, propelling all of him forward and shoving him to the maximum penetration all at once in the gleefully squealing centaur.

The horse fucked hard and fast, scrubbing Sherri’s insides frenetically as instinct demanded with no finesse. Balls slapped teats accompanied by the wet untidy noises of air and pussy juice continually and repeatedly out of the way of a penis that moved at an inconsiderate, alarming rate.

The experience was not a long one, but it was more than enough. Turned on beyond endurance by the rough fucking Sherri gushed femcum around him. The internal movements of her orgasm were bullied indiscernible by his harsh rhythm though she felt every one.

Her stud unloaded not long after. The tip of his cock flared as he pumped a pint of horsy baby batter almost directly into her cervix, bulging exquisitely against the inner edges of her vaginal canal.

She got to enjoy the afterglow for almost half a minute before the feral, not programmed by nature for drawn out cuddling, stepped back. He slid off her to the side as his expanded cocktip popped messily free from her folds to send a splash of mixed cum falling to the ground between her hind legs.

“Ooooohhhh goooodddd.” Sherri sighed blissfully. “I needed that.”

Her lover rubbed his head against her side, an appreciative grooming gesture that also pushed her toward his herd.

“Good for you too, huh, buddy.” She rubbed at his shoulder in reciprocation. “Sorry, not going to be staying. I’ll drop in if I’m in the neighborhood though, huh.”

Sherri stepped away, turned, and began to gallop back the way she’d come.

The spent stallion made as if to follow briefly, but stopped before getting too far from his herd. He’d just blown his load too hard to want to do any chasing. If the strange mare with the funny head wanted to run off on her own instead of staying in the safety of the group, he wasn’t gonna be crazy enough leave his whole harem- or this patch of really excellent grass- unattended to chase her. Shame he wouldn’t get to pound that snatch again. But what a weirdo.

Wendy was trying to look nonchalant when Sherri trotted back up to the truck, laid back against the rear window in the open back. Sherri thought she had the same vibe as the last time she’d caught her friend masturbating. Even money the human’s panties were soaked.

“Hey. Back pretty fast. Everything go…?”

Wendy’s vague gesture could have meant anything, adding essentially nothing to the content of her equally vague question.

“Oh, you know how it is. Busy guy, no time for long dates out in the wild. But yeah, I got the stuff.” Sherri tossed back casually. “Grab a sample vial and come get it.”

After a long moment, the penny dropped. “You- Why me?”

“It’s hard for me to reach all the way back there, you know?” Sherri patted herself on the furred back casually, grinning at Wendy’s blush. “Maybe I could manage, but the back strain and I’d get the label all sticky…”

“Oh. Uhhhhh…” A snap decision happened behind Wendy’s eyes. The human was, in the end, a professional at heart. And maybe a closet perv in her bones, too. “Yes. Hang on.”

Wendy rifled through their equipment bag, setting aside the untouched electrostimulation probe and dart gun, shoving aside the glorified sex toy of the semen collector, and retrieving one of the ten- milliliter vials and a smaller ampoule of preservative fluid. When she turned around she was startled a little by Sherri’s ass. The centaur had pressed it up against the edge of the pickup’s lowered tailgate, the curve of her rump resting just on the flat surface, plump recently-bred pussy squished slightly open from the weight. Sherri was grinning back at her.

The human researcher steeled herself, and shuffled forward on her knees, unscrewing the vial’s lid. “You’re on the pill or something, right?”

“Nah, I’m definitely knocked up.” Sherri met Wendy’s incredulous stare for a full ten seconds before breaking down in a giggle. “No, I’m not on anything, but I’m not in season for another week or two. No foals for me, probably.”

“You’re fine with ‘probably’?” Wendy grumbled as she looked down at the centaur’s pussy. She was trying to figure out a way of doing this without making it weird.

“I want kids anyway.” Sherri answered casually. “I’m in a good place financially right now and I’d have a whole year to get ready.”

Deciding that this was going to be weird no matter what, Wendy just pushed the opening of the vial into her friend’s cooch, just above the big horse-clit. With her other hand she slipped a finger into the pussy, scooping the trickle of thick horse jizz into the glass tube. “Really. What if it was a horse? Just, all horse.”

“If they take after dad’s good looks they’ve got a great career as a show horse. And I will be very proud of them.”

“You’re fucking with me now.”

“Pretty sure you’re the one finger-fucking me.”

“There’s barely any here.” Wendy’s voice dripped exasperation. “Your crush squirted it all deep in there.”

“Oh, yeah. Hang on. Gonna try to….”

Sherri’s brows knit in concentration as she tried to work her muscles, seeing if she could maybe just push some of the cum out.

“Whatever you’re trying it’s not doing much.” Wendy observed after a while.

“Well… shit. I really don’t want to go back and tranquilize him. Would kind of ruin the mood, you know?”

“I’m not sure what it would do to our results either.” Added the other woman. “… Does sperm count go down on round two? Your collection method might fuck with that anyway.”

“We mostly want sperm viability and gene tests, so whatever. It’d suck to knock him out after he was so helpful though.” Wracking her brain for options, Sherri’s backward glance at her uncooperative rump slid over the collection kit. “Hey, what about the stim probe?”

“You just said you didn’t want- Oh.”

“It’s build to make muscles tighten up, right? So maybe if we get it positioned right…”

Now fully engaged in the problem, Wendy didn’t balk at the prospect of using a shock probe on her hybrid coworker. Swiftly retrieving and lubricating the forearm-length bullet-shape of it she turned back to Sherri’s rear. “Um… Anal or vaginal insertion, what do you think would work better?”

“If you put it in my puss it’ll just block anything getting out, right?”

Wendy plugged the probe cord into the power box as she nodded, and neatly lined the rounded tip up with her friend’s anus.

“Hooo, that’s cold.” Sherri winced as the chilly lube eased the probes entrance. The metal contacts on the underside made for a separate coldness as they slid past her donut, three lines that would shortly carry current into her. “All right, fire it up.”

At her request the other researcher positioned the test tube at Sherri’s snatch again and with her other hand flipped the on switch.

The centaur’s entire hind end twitched at the unexpected sensation. All the nerves in her anal wall, and a bit past, activated indiscriminately in a quite literally electrifying sensation. Sherri’s little shriek almost caused Wendy to turn the machine back off immediately.

“Eeeeesssh that feels strange!”

“Does it hurt?”

“Only at first. Woo.” Sherri released a puff of air, eyes wincing closed as she fought to keep still. Gradually the confusing discomfort eased into a weird pulse with her anal muscles working rhythmically on their own. “That’s kind of intense.”

“Uh huh.” Scrutinizing the centaur’s folds for any sign of the desired leakage and finding no result she asked, “Are you okay if I turn it up a little bit?”

“Just go slow.”

About ten minutes and several adjustments later Sherri called a stop to the plan. “I don’t think this is working.”

“…Doesn’t look like it.” Came the reluctant agreement. Though the equine cooch had flexed and clenched several times, it hadn’t shot out fountain of stallion splooge as Wendy had hoped. The motions didn’t even seem a direct result of the electric charge, not particularly rhythmic. “Maybe it’s not reaching far enough. The probe is all the way in though, so I’m not sure what else we can do. That really doesn’t hurt? It’s set pretty high now.”

“Not exactly. Feels kind of interesting, actually.” Sherri decided to voice the idea that she had been formulating. “I’ve been thinking, though. If studly over there can fit, you could probably reach in with your arm…”

Wendy leaned over the side wall of the truck to shoot her a blandly accusing look.

“You’re getting off on this.”

“…Maybe a little.” Sherri admitted. “But it ought to work, right?”

Grumbling, the other woman rolled up her sleeve and pressed her hand against the centaur vulva, pressing the dainty fist against the moist cleft until it popped in. Immediately engulfed to the wrist, she had to work to press in, pausing at about six inches deep as a wobbly icy/warm tingle caressed over her knuckles.

“That does feel weird.”

“Hmm?”

“I can feel the probe on the top of my arm. Didn’t think to turn it off.”

“Well, it should be safe…”

Wendy didn’t think her friend’s casual tone was all that convincing. But she would have had to pull out of Sherri’s cooch to reach the off switch from this position, so if the centaur was enjoying this a little too much she might as well just live with it. Giving a horse an orgasm with the thing had always been in the plan anyway.

Sherri’s obvious arousal at least made the process relatively slick and easy. The love tunnel squeezed and moved around her arm as she sunk further and further in. An especially hard clench hit as the human’s elbow squished her clit on its way past.

“Wendy, I think I’m going to-“

“Whatever.” Wendy grunted through gritted teeth. “Just try to stay still, I’m almost there.”

Climax hit and yanked wetly on her arm, pulling hard on the woman’s shoulder despite Sherri’s attempt to do as she asked. Wendy found her face pressed into the centaurs rump at roughly the same time. Horny equine with a hint of watermelon-agave shampoo filled her nostrils as her bare arm was wetly flexed around.

Thinking quickly, she opened her hand, scraping fingers against the rippling insides. Other hand planted on Sherri’s haunch she pulled away, glistening arm coming free with a schlorp that sprayed the bed of the truck with femcum. A smattering of white driblets came along for the ride, creating a spotty outline of the splash zone.

Wendy, wet up to the shoulder, did her best to ignore her coworker’s moan of satisfaction as she scraped the handful of jizz she had scooped out of her into the test tube. She broke open the ampoule and emptied it into the vial while the now much more visibly creampied Sherri recovered.

“You owe me.” She grumped at the orgasmic centaur. Screwing the cap onto the vial she wiped it and her hand off pointedly on Sherri’s seat cushion. “And we’d better hope your girl juices don’t mess up the tests.”

“Should be fine.” Sherri assured her through panting breaths. “Wooo. …Starting to cramp a little back there. Could you take that out?”

Wendy cut the power to the electric probe before matter-of-factly pulling it from her friends ass and dropping it into the can of cleaning fluid. “Glad you had fun. Seriously though. What if you get knocked up?”

“For real, it’s fine.” Sherri turned around to face the truck, hoisted her forelegs up onto the reinforced tailgate, and started the tricky maneuver of crawling forward and pulling her back legs up to join them. The wobble in her hind legs provided a little extra handicap. “I’m like ninety-nine percent sure I’m not fertile right now. And if I do have a baby centaur, great, and if I have a baby horse I’ll find them a good home. It’s really not as big a deal as you humans make it out to be.”

“…I’m sure you’d be a great mom. Guess I can see how the pregnancy part isn’t as big a deal for you, at least.”

“Oh god, no, for real.” The centaur winced theatrically. “You humans with the swelling up like a balloon and waddling around and the extra-large mood swings. Wouldn’t trade all that for the extra three months, no thank you.”

“For real.” Wendy agreed emphatically.

Wendy carefully wrote the time, date, and location on the collecting vial’s label- slimy despite her best effort, but it would be fine- and slipped it into the cooler full of ice packs they had brought along for that purpose. She vaulted out of the back and slipped into the driver’s seat, rummaging one-handed through the bag she left in the passenger side for a towel.

“I’ll get started on my centaur pills in a week though, on schedule.” Sherri added through the open back window, as she buckled the complex harnesses that served as her seat belt. “We don’t get weird about these things like you humans, but it’d still be a hassle to find a foal a good home”

“…Wait. Were you.” Wendy paused, then finished the question. “Planning to do all the sample collections this way?”

“Probably not all of them. Unless they’re all that handsome.”

“Sherri! I am not reaching down your vagina every time!”

“I could let you bang some of them if you like. I do owe you.”

“Sherri!”

“Don’t tell me you weren’t watching. Can’t blame you at all for wanting in on the hot studs.”

To her chagrin, Wendy’s spluttering eventually ended in, “-Wouldn’t even fit– No, I mean-“

“You’ve got a point there.” Sherri smilingly let her friend untense a little before adding. “I’ll keep an eye out for any cute ‘short prince’ ponies, how about that.”

The response was an exasperated, embarrassed wheeze full of ‘can’t even’.

“You’re too easy to tease, Wendy. For real though. Say the word and I’ll find a way to set you up.”

“…Let’s… just stake out the next grid for now. The gene diversity survey isn’t going to finish itself.”

“On it.” Sherri agreed, giving her furiously blushing workmate with a pat on the head. “East next… And let’s crank up the tunes, we should still have good radio reception.”

The End

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