"First things first, we should probably get inside before someone sees us." Dave said, looking over his shoulder. Thankfully no one was paying them much mind. Dave was standing in the doorway, his body shielding Amy's from view.
The two quickly shut the door and stared at each other. Amy's eyes were drawn to Dave's new cock, and she struggled to resist the stirring in hers. It was bigger than hers, a whopping 2.5 feet long. It hung, semi-flaccid out of the top of Dave's fly. Amy could see the bulge of his larger testicles pressing against his jeans. His sheath was barely visible.
Meanwhile Dave was inspecting Amy's body with a closer eye. Aside from the horsecock and balls between her legs, she had also developed a long horse tail, complete with chestnut hair. A thin layer of horse fur covered most of her body. Dave wasn't sure how big Amy's breasts had been before this craziness happened, but he knew they had gotten bigger. Her nipples stuck out, erect and now entirely black. Amy's feet also seemed larger, thicker almost. Her nails were black too, and covered most of her toes.
Realizing they were staring, both dropped their gaze and muttered an apology. Being a guy, and having had a lot more experience controlling himself, Dave was able to make himself soft again. His cock slowly shrunk back into the dark skin that was at the base of the shaft. Dave saw that even when unaroused, the head of his cock stuck out of his sheath just a bit. He'd never be able to get the zipper of his pants closed now.
Amy felt even more embarrassed as it became obvious she'd been aroused by Dave's body. Her cock slide out of it sheath and flopped forward in a similar fashion how Dave's had been a few moments ago. Her face was flushed, from embarrassment and her arousal.
"Sorry." Amy muttered, doing her best to cross her muscular legs over her erection.
"It's okay Amy. I wouldn't expect you to be able to control that thing. Takes a lot of practice." Dave said sheepishly. Truth be told, he was having a tough time keeping his cock soft too. Watching Amy's extend away from her thick, but still feminine body was making something inside himself grow hot. And he knew that if he allowed his urges to take control, he'd end up like Amy. On his way to becoming a horse, or horse person.
"What did you do yesterday? You weren't abducted by aliens or kidnapped by a crazy scientist were you?" Dave asked, in an attempt to distract himself.
"I may as well have been." Amy sighed. She told Dave about her trip to the farm, and finding that vial of chemicals. And then how she'd fallen asleep and when she woke up she had a cock and balls between her legs. Amy's face burned red as she told him how she'd been overwhelmed and jacked her new appendage off. When she was done speaking, Amy shuffled over to the couch and put her head between her hands.
Dave waddled over to her, slowly as he wasn't used to having such large equipment attached to his body. Walking was made all the more difficult since he was wearing pants, while Amy was totally naked.
"I don't know what to do. I can't walk out of the house like this! And I don't have anything to wear." Amy moaned. Dave put an arm around her and rubbed her back with his free hand. That's when he saw the beginnings of a mane on Amy's neck. An almost perfect line of dark chestnut hair ran from the base of her existing hair to her shoulder blades. Her ears appeared to be tapered to points as well.
"We'll think of something, don't worry. Just have to get a little creative." Dave said, deciding it would be best if Amy didn't know about her other changes.
"Thank you." Amy leaned against Dave's body. His strokes were comforting, and Amy buried her face into the crook of his neck. She breathed in slowly, noting his strong scent. It made her feel very calm, but at the same time very hot.
A bit of movement caught Dave's eye, and he pulled away from Amy for a moment. Then his eyes widened and he pushed her further away. Amy's cock had risen so that it was standing erect between her breasts. The head had puckered even more as her erection built, a bit of clear liquid sliding from the hole in the center. Pre cum.
"Amy, calm down. You don't want to do this." Dave said. He got up, and watched as Amy stared at him hungrily. Her cock was shaking in front of her, and her balls seemed to inflate more. Behind her, Amy's tail lashed back and forth. She slowly advanced on him, her mind lost amidst the intense heat she had growing in her chest.