Author's Notes: This is kind of a silly story that I am "playing straight" as in I'm actually going to put the same amount of work into this as everything I write... but it's still not something that I think anyone should take seriously. This whole thing is based around a joke that me and some old friends had a very long time ago (20-ish years) and even though we've all kind of gone our separate ways I never forgot this inside joke and to this day it still gets a chuckle out of me.

There's a popular brand of shampoo that you can buy at most major retailers. For their sake, and so that this website has zero chance of appearing if you Google their name, I'll refrain from saying the brand. But it started out as a shampoo specially formulated for show horses and at some point I guess the owners of said horses started using it too, told the manufacturer "hey this works great on my hair", and now you can buy this stuff both at Petsmart AND Walmart. So the inside joke my friends and I had, obviously, is "what happens if you use it to wash your hair but because it's meant for horses it just turns you into a horse".

That's it. That's the entire premise. I'm certain someone else has probably thought of this idea too; there might be another story out there just like this one because I was beaten to the punch, I don't know. It seems like a very low-hanging idea for a transformation scenario. Anyways, enjoy; and, my apologies.

"Hey, what is this?" Stephanie asked as she spotted a bottle of something sitting on the kitchen countertop while getting a drink from the refrigerator.

"Oh, that's that stuff right?" Trey, her boyfriend, replied glancing over from the couch for a split second before focusing back on the game he was playing. "The shampoo you were talking about? I got it when I ran to the store this morning."

Stephanie picked up the bottle and looked at it more closely.

"No, this isn't the one," she answered almost immediately. "This one is covered in pictures of... little horses?"

"Yeah that's what you said though right? It has the animals on the bottle?" Trey said, not looking away from the television this time.

Stephanie and Trey had been dating off and on since they'd met in high school but didn't get serious about their relationship until after graduation. Stephanie was a full time student at the university while Trey took up trade school to learn how to weld and fabricate, though to pay their bills he'd taken up an assistant managerial role with a local landscaping business. By all accounts they were the standard young American couple, a career-focused homemaker and her blue collar partner working toward their shared goal of home ownership and, perhaps, starting a family. For now though, they were just renting a house that they had to themselves.

"Yeah, animals. Kangaroos, though. The Australian brand," his girlfriend replied with a sigh.

"Oh... well... shit, mybad," Trey said, realizing his mistake. "I didn't see the kangaroo one. I just saw the horses and remembered you said something about animals."

"Was this even in the section with the rest of the normal shampoo?" She asked.

Trey paused the game he'd been focusing on to glance back over at Stephanie.

"No Steph, I got that one from the veterinary section just for you because you said you wanted the animal shampoo," he said with a sarcastic tone and visible sneer.

"Yeah, it was in the same section with all the expensive salon stuff. That one's not cheap either. It says it's for people too even though they originally made it for horses," he added, less sarcastically.

By now Stephanie had popped the top of the lid backward on the bottle and raised it up to her nose.

"Well... it doesn't smell like a barn, so that's good," she said with a shrug.

"Hey, I'm sorry babe, it probably works pretty good though?" Her boyfriend replied. "I mean, horses have hair, right?"

"Yeah Trey, horses have hair. Most animals have hair," Stephanie jabbed, now adopting a slight sarcastic tone of her own.

Trey sighed. "You get what I mean. Long hair," he added with emphasis on the word "long".

Stephanie flipped the bottle around a couple of times as she scanned the labels and read what was in it to see if it was something she trusted enough to use on her own hair.

"...you think it's safe though? We're out of shampoo and I was going to take a shower right now so like, this is fine?" She asked.

"Yeah. It's fine," Trey replied, absorbed in his game again. "I don't think it's going to make your hair fall out. If it did we'd probably see a lot more bald horses or something."

"Fine. But if this screws up my hair you're on the couch until it gets fixed, however long that takes."

Trey shook his head and laughed.

Stephanie retreated around the corner of the kitchen toward the bathroom with the bottle of shampoo in her hand. She set it down before going into the master bedroom in the neighboring room to grab some underwear and loose fitting clothes for the remainder of her evening at home and brought them back into the bathroom. She shut the door, and a few minutes later Trey could hear the water turn on as his girlfriend presumably stepped into the shower.

About fifteen minutes had passed. Trey was still intently focused on the game he was playing, but a sudden noise quickly broke his concentration. A shriek rang out from the bathroom loud enough to go through the walls and sound as if the person doing it was standing right next to him.

"Steph??" He called out, not even bothering to pause his game.

When she didn't reply for a few moments, he practically leapt off of the living room couch and bolted through the kitchen toward the bathroom.

"Steph? Are you okay in there?" He asked outside of the bathroom.

Still no answer. Trey attempted to open the door but it was locked, and he could hear that the water was still running.

"Hey! Stephanie! What's wrong? Did something happen?" He asked again in a panicked tone, still cranking the doorknob around fruitlessly.

"I- I'm fine..." Stephanie finally replied from the other side of the door.

"Are you hurt? What happened?"

"I... I don't know..." she answered weakly.

"What do you mean you don't know? Why did you scream? Is there a mouse in there or something?" Trey asked, still sounding tense but very gradually easing down now that his girlfriend was finally responding.

"No. I just..." her voice trailed off.

"Stephanie what is going on? Do I need to call 911 or something???"

"Trey, you're not going to believe me if I told you," Stephanie replied.

"Oh my God... can you stop being so cryptic for once? Did the pipes come out of the wall? Mirror fall down? Is something broken?"

"No, nothing's broken," she said.

"Then what the hell is making you scream bloody murder in there?" Trey jiggled the doorknob again. "Open this door."

"...I'm afraid to."

"What? Why?" Trey paused for a moment. "Oh no... oh fuck... did your hair actually fall out because of that horse shampoo? Is that what this is about?"

"Uhh... no, it didn't fall out," Stephanie said, still on the other side of the door.

"Thank God," Trey muttered to himself under his breath.

"Steph you're gonna have to let me in or something if you want me to help fix whatever's gone wrong."

"If I open the door do you promise you won't freak out?" She asked meekly.

"Why would I freak out?" Trey said.

"Just answer the question. Do you promise me you won't freak out?"

"Sure, yes. I promise! Whatever. Steph, just open the door already."

Several seconds of silence followed, ended by the distinct low clicking sound of the lock on the door being turned the other way. Trey watched from his side of the door as the knob slowly turned on its own as Stephanie gripped it from the other side. The door popped open slightly at first, swinging inward away from Trey, and then gradually eased open the rest of the way. Trey's eyes met Stephanie's, and for a moment neither person said anything.

"You cannot be serious. Am I dreaming? This is a dream, right?" Trey finally said.

Stephanie was standing on the other side of the doorway in the bathroom, nude, though she didn't look remotely close to the way she did when she entered the room half an hour prior. She was the same height, same long flowing blonde hair too, but her lithe body was now covered in a very fine chestnut brown fur. Her hands were mostly the same, but her feet had shifted slightly into a sort of cloved hoof hybrid. From her backside Trey could see that she was now sporting a tail comprised of the same long blonde hair that she had on her head, too. But it was her head that had undergone perhaps the most drastic change. Her face had elongated out into a very pronounced muzzle with a large black-skinned nose; her ears had curved inward slightly, adopted pointed tips, and moved up near the top of her head.

She was a horse. Trey was looking at an anthropomorphic horse.

"I- I hope it is... this feels like a nightmare," Stephanie said, her voice cracking slightly.

"Babe, you're..." Trey's voice trailed off as he stepped into the bathroom and wrapped his arms around his girlfriend. "We'll uh, we'll figure something out."

Stephanie didn't respond, she simply rested her head against Trey and began to sob.

"I mean... your hair does look good at least," he added, trying to think of something consoling to say.

"Trey!" Stephanie raised her voice as he jerked away from his embrace. "You motherfucker!"

Stephanie stormed out of the bathroom. Moments later Trey heard the unmistakable sound of the nearby bedroom door slamming shut.

"Hey! Steph!" Trey called out as he quickly followed out the door and around the corner.

"Steph, hey I'm sorry. I was just trying to think of something nice to say," Trey said through the bedroom door this time.

There was no response from the other side, though Trey could very faintly hear the sound of her crying somewhere on the other side of the door.

"Steph, babe, open the door. Please."

"It's not even locked," she finally replied.

Trey turned the doorknob and realized she was right. "Oh..." he said to himself, feeling stupid.

Stephanie had sat herself down on the edge of their bed, her legs swung over the side as her elbows rested on her knees holding her head in her hands. Trey quietly made his way over to the bed and sat down beside her, placing his arm around her body and onto her far shoulder.

"I uh... I don't really know what to say to try and console you right now..." he said somberly.

"I don't believe this," Stephanie said, her head still hanging in her hands. "This is real? This is fucking real? I'm fucking ugly!"

"No, don't say that sweetheart," Trey replied trying to sound reassuring, though not having the faintest idea what to actually do in this situation. "This is... weird, yeah, but... you're not ugly or anything."

Stephanie sniffed a couple of times before finally raising her head to face Trey.

"Really, Trey? I'm a fucking horse now!"

As Stephanie's eyes locked on Trey's he simply stared back at her for several moments in silence. Yeah, she was a horse. Not the actual kind you'd see on a farm or at the race track, but something very perfectly in the middle between human and equine. Even though her form had changed substantially, Trey noticed her eyes were the same deep hazel that they always had been. She was still Stephanie; she still sounded like her, acted like her, spoke like her... she was just, different now.

Without really thinking or knowing what to say Trey, already sitting directly next to Stephanie, leaned his head forward and gave her a quick light kiss. He wasn't sure why; it just felt right in the moment, something to diffuse the situation and maybe make her feel better. Understandably, he'd never actually kissed a horse before so rather than catch her lips Trey wound up pecking her right on the front of her nose between her nostrils.

"...what was that for?" Stephanie asked.

"Remember when we were still in high school and you tagged me in that post with the joke about asking if your boyfriend would still love you even if you turned into a bug?" Trey replied. "Well, you're not actually a bug but I feel like this is as close as we might get; the answer is still 'yes'."

Stephanie chuckled once as she recalled the memory, her laugh coming out as a single huff as she liked to do just with a more gruff sound to it.

Trey smiled and leaned in to give her another kiss, this time with Stephanie following suit. He met her lips this time, his free hand gently holding around his girlfriend's neck and shoulder while the one he had previously put around her when he sat down moved down her body to hold her at her side. As their kiss broke Trey started another, and another. Stephanie's arms gradually found their way around her boyfriend and as she embraced him she felt both of their bodies shift backward slowly onto the bed.

"Trey, are we really... right now?" She asked. "Like... this?"

"Why not?" Trey said with a grin as he gave her another quick smooch and placed his hand on her lower stomach.

Stephanie didn't say anything, she just smiled and resumed kissing her partner whose hands were occupied exploring her changed body. Everywhere Trey's hands touched was covered in a short fine fur, soft like an expensive paintbrush and positioned in such a way that running his fingers against its grain ruffled it noticeably. The places without fur that were just skin had adopted a very dark gray pigmentation, almost jet black but not quite. Trey spotted it mostly on Stephanie's nose, near her eyes, and, more sensually, her nipples. She hadn't gotten dressed since stepping out of the shower so Trey was able to see quite distinctly each of her firm nipples and the little bit of areola around them showing through the short fur covering her breasts. He eagerly palmed her chest softly, letting his hands slowly find their way to her sensitive tips and giving each of them a gentle squeeze.

"I guess... do I call these teats now?" Trey said with a laugh.

"Sweetie... if you're trying to kill the mood you're doing a fantastic job of it," his girlfriend replied rolling her eyes.

Trey blew a raspberry at Stephanie before resuming what he was doing, now letting his right hand travel down her body toward her crotch passing over a very slight tuft of brown fur before reaching another smooth patch of near black skin. He ran his fingers across her womanhood, able to tell just from touch alone that it too had changed. There was a noticeable firmness to her pubic area, her lips very plump and pronounced now. Just touching her was enough to make Stephanie moan softly and as Trey kissed her again he noticed that both of her pointed ears fluttered a couple of times on their own.

All of it was strange to Trey. Stephanie's body was so radically different now, but still somehow "the same" in the most basic way. She was still a woman, still his girlfriend, and responded just the same to being touched and caressed... but also responded in new ways that were unique to her altered form. Seeing her flutter her ears got him going in a way he couldn't pin down; it was exciting, exotic in a way. But it was still Stephanie so it somehow didn't feel "weird" to him at all. Trey roused himself from his laying position next to Stephanie and pulled his shirt off, tossed it aside, and began to unbuckle his pants.

"Ready to learn to ride a horse?" Stephanie said with a giggle.

"I know you're trying to play off the teat thing about killing the mood or whatever," Trey started as he kicked his pants off, "but you're underestimating the resilience of the mind of a very horny man."

"God... you are such a pig," Stephanie said with a groan.

"...says the horse," Trey answered with the biggest knowing grin.

"Oh my God... fuck off," she said with a laugh, realizing she'd set herself up for that retort.

Trey straddled himself between Stephanie's splayed legs and looked down at her body. Just like everything else about his girlfriend even her genitals were something between human and equine. Trey realized he'd never actually seen what a pussy on a female horse looked like, or if he did it was something in passing driving by a farm or seeing it on a carriage somewhere in town. In other words, it wasn't something he'd ever paid any attention to, not that he ever had felt the need to know otherwise. But, looking down at his girlfriend's he had a chance to actually see one now. It intrigued him, the way her outer labia had puffed up into a plump mound of black flesh, her lips becoming more pronounced and larger than they were before. It was definitely "animalistic"; that was the best way Trey could describe it, and yet the thought of it drove him wild. Something taboo, but still somehow safe.

He pressed the underside of his cock down against her lips, grinding his length across her opening and feeling how soft her skin had become. After just a couple of passes however Trey stopped when he noticed Stephanie had seemingly flexed her lower muscles a couple of times, her lips parting slightly for a second to expose just a tiny bit of the pink flesh hiding inside.

"Wait... are you doing that?" Trey asked, glancing back up at Stephanie's face.

"I uh... n-no..." she replied sheepishly. "It's like... it's doing it on its own. Like... uh... like hiccups, or something?"

Neither of them knew anything about equine arousal. The contractions were strange, but erotic in a way. Trey thought of it as her body begging him to take it, which of course only served to continue to fuel his own arousal. He ran his fingers along her lips curiously, slipping a couple of them inside every time Stephanie winked. Every time she did it he could feel how slick her inner walls were. He was as eager to fuck her as he was to just continue exploring every single thing that was different about her, though he figured he could very easily do both at the same time.

"Hang on..." Trey said as he scooted back on the bed toward the edge of it.

"What? Where are you going?" Stephanie asked.

"I'll be right back, just give me a minute. I have an idea."

Trey hurried out the bedroom door elsewhere in the house. Seconds later, Stephanie heard the water in the bathroom turn back on.

Another ten or so minutes passed, just like before. Stephanie heard the water shut off though it took a while before she heard anything else. Then, there was a knock on the bedroom door.

"Knock knock," Trey's voice said from the other side.

He didn't wait for a reply; seconds later the knob turned around and the door slowly swung open, revealing Trey standing in the doorway.

"...holy shit... Trey," Stephanie uttered from the bed, her mouth slightly agape as she stared across the room at her boyfriend.

He was different now too, just like her. Wearing only a bath towel around his waist, Stephanie could see that he'd also become a horse; his entire body was covered in a dark chocolate brown fur, the hair on his head having turned dark black and grown out considerably with a matching tail. His new equine figure accentuated his already toned body, his face and jaw still just as defined as a horse as it was when he was human. He was... attractive, and Stephanie didn't know if that was her thinking that on her own or something pertaining to her earlier transformation letting her recognize things about her boyfriend's new body that she may not have otherwise if he'd been the one to go first instead of her.

"So... what's behind the towel?" Stephanie asked with a grin.

Trey didn't say anything in response, he just reciprocated her expression. He tugged on the rolled knot at the side of the towel and let it drop to the floor around where he was standing. Just like Stephanie, that part of his body had changed too and, also much like her, had adopted a significantly more equine look. If Stephanie balled her hand into a fist it would about the size of each of Trey's balls now, both of them hanging heavily from his crotch in a taut sack of smooth black flesh. And, hanging down in front of them his manhood stole the show. His human cock had morphed into that of a stallion's, complete with a flattened head, prominent medial ring, and a loose collection of bunched up skin at its base acting as something of a pseudo-sheath. Its pigment started black at its base but broke up into a mottled pinkish color about a third of the way up its length that resulted in the upper half of Trey's shaft being in that lighter tone. Flaccid, his shaft hung nearly as long as his forearm.

The mere sight of Trey's new package was enough to bring Stephanie to full arousal again, her mare-like lips immediately clenching and winking at the thought of taking that maleness inside her.

"Like what you see, I take it?" Trey said with a laugh, watching his girlfriend's body respond to what she was looking at.

"I'm dreaming, right? If this is a dream you have to tell me, like when someone asks if a dealer is a cop?" She replied.

"I don't know," Trey said with a shrug as he placed his hand on his manhood and caressed it. "Feels real to me?"

Trey climbed back into the bed in front of Stephanie and got into the same position he'd been in earlier resting on his knees between her open legs. He leaned down on top of her, touching the tip of his muzzle to hers. Both of their lips parted as they kissed, their longer equine tongues slipping across one another as Trey embraced Stephanie while she slid one of her hands behind his neck to hold him.

The kiss broke slowly as Trey gradually roused himself back up into his kneeling position. He looked down at his shaft, now fully erect and reaching almost as far up as his girlfriend's navel. As a tradesman unafraid to get his hands dirty he never had an issue feeling a sense of "manliness", but the sight of such a massive avatar of the male body filled him with a sense of pride that he didn't even have the words to begin to explain. His girlfriend's marehood was his to take with his own matching set of equipment.

Trey shuffled himself backward slightly to get some space as he rubbed the head of his cock across Stephanie's lips, spreading her arousal around and teasing the first inch or so of her inner walls each time her passage winked. Slowly, he pushed the head of his shaft forward with his hips, meeting a little bit of resistance at first but easily slipping his first couple inches inside as Stephanie relaxed between her involuntary clenching. Stephanie's eyes widened as she felt her canal quickly spread open to accept her boyfriend's shaft, filling her out more fully than he ever had before. She clenched up around him, this time on her own and not the ones she couldn't control.

Trey moaned softly feeling every little bit of Stephanie's inner walls tighten up around him as he slowly eased himself further into her. He was surprised she was able to take his girth so easily, though he also realized that given the changes that had happened to both of their bodies her womanhood had probably grown on the inside just as much as its more pronounced appearance on the outside implied; she definitely wouldn't have been able to accommodate him if she were still fully human, though. That much he knew.

The medial ring of Trey's horse cock passed into Stephanie, followed by a couple more inches of the length behind it. She felt fathomless, and Trey wondered if he'd eventually fit his entire length into her. It seemed completely impractical; she was still the same size physically, he'd have to eventually reach... something? Stephanie moaned as she tightened up around Trey again, her vocalization turning into a slight whinny at its end. Her horse-like sounds met Trey's ears causing him to grin and lean back down to kiss her once again. It sounded so primal and yet so passionate, a lustful moan unlike anything he'd heard from her before. He began to pick up his pace of thrusting as they kissed, the head of his shaft eventually bottoming out and meeting the barrier to her womb with just a couple or so inches left to spare on the outside.

Stephanie moaned again, this time into the kiss as her ears flicked several times. Trey huffed a couple of times, his grunts also now having a noticeable equine-like quality to them. Reaching so far into his girlfriend, his lover, and touching her so intimately at her deepest flicked a switch deep in his mind that heightened his arousal. He broke the kiss to arch his back slightly and moan, Stephanie joining him as her entire canal gripped his maleness tightly as she reached her climax. Her body shuddered in intense pleasure, her legs quivering, her voice cracking as she whinnied again. Trey gasped as he felt her tighten up around him and pulse in deliberate rhythmic contractions.

He barely made it another few thrusts into her before he reached his peak and joined her over the edge. His equine shaft throbbed powerfully, the first couple of flexes causing its head to fan out into a brilliant flare. His shaft pumped several times before he finally felt an enormous load of seed blast from his manhood, one jet of it easily more than he'd release in an entire climax before. That was only the first of many; the stallion buried his shaft inside of Stephanie, rutting and fucking her through his orgasm as every throb of his cock shot another generous load of cum into her, so much that it quickly began spilling out and running down onto the bedding underneath them.

Trey had never felt an orgasm last as long as this one, and neither had Stephanie. As his emissions stymied into a trickle Trey leaned back down and kissed her again, tightly wrapping his arms completely around her and caressing her body.

"Fuck... babe, that was incredible..." Trey said as a whisper into her ear as their kiss broke and he laid atop her.

"Yeah..." Stephanie replied gradually catching her breath. "I don't think I've ever cum so hard in my life... I can still feel little sparks of it even now."

"I love you so much," he said with a soft sigh and gentle squeezing of his arms.

"Gosh, Trey," his girlfriend replied with a grunt as he hugged her tightly, realizing that perhaps he was now not only hung like a horse but also as strong as one too.

"I love you too honey," she continued, nuzzling her face against his and whinnying slightly.

The two embraced each other for a few moments until Trey got back up into his kneeling position and slowly pulled his softening equine shaft out of her. He shuddered slightly, feeling what remained of the flare on its head slowly drag across her slick inner walls until it popped free and let another small dribble of his horse seed flow out of her.

"Man... we really made a mess didn't we?" Trey said with a laugh as he surveyed the "damage".

Stephanie chuckled as well. "Yeah, we should probably get cleaned up again."

"Good idea," Trey said as he scooted back and swung his legs over the edge of the bed to stand up.

"I heard about this neat shampoo they make," he added. "It's meant for us, but people can use it too I guess. I think I spotted a bottle of it in the bathroom when I was last in there. Care to join me?"

"Too bad your sense of humor didn't grow as big as your cock," Stephanie sneered with a laugh.

Trey laughed in response with her, motioning for her to follow.