"Mmm... Kelly..." Cole said as he broke the kiss off from Kelly for a moment. "You're so hot..."
"Mmm, don't you know it," Kelly said with a grin as she pushed him back onto the bed, she pulled her shirt off to reveal her bare breasts underneath. She felt a heat growing in her pussy, but didn't pay it any mind, she just wanted to be fucked right now. "And I'm all yours for tonight."
"Oh... I'm looking forward to that," Cole said with a grin as he unbuttoned his pants and pulled them off with his boxers. He looked a bit confused at his cock that was standing erect, it looked bigger somehow, and different. "Fuck... what's..."
Kelly moaned as she stared at his cock, it was so much bigger than she had expected and she felt her pussy getting wet at the thought of that monster inside her, it had to be at least a foot long, a real stud. "Mmm, you didn't tell me you were hung like a horse. I'm going to enjoy this, stud."
"Then you're my hot little filly," Cole said with a grin as he gripped his growing cock in his hand. "Maybe I should mount you like one."
Kelly grinned at that as she pulled off her pants, revealing her wet pussy underneath. Her pussy lips had already started to puff out and start to migrate, but if either of hem noticed they didn't care. She climbed up onto the bed and moved onto all fours while Cole got up, watching as she wiggled her ass at him.
"What do you say, stud? Your filly is ready for breeding," she moaned. The heat in her pussy was unbearable, and she knew the only way to quench it was to be bred by a true stallion. "Fuck me!"
Cole didn't need any further prompting as he grabbed her ass and thrust his cock into her pussy. She smelled so good which just made him more and more aroused as he thrust into her, his cock stretching her pussy like nothing else had before. "Fuck... you're so tight..."
"And you're so fucking big..." Kelly moaned as she felt him penetrate her more, it felt like no other cock that had ever filled her before, and she loved it.
What she couldn't see was that with each thrust, reddish fur was already starting to spread across her body. Her breasts were bouncing with each thrust, but they were starting to shrink down into her chest as her body barreled outwards. Her mind was being consumed by thoughts of sex. Images of her and men were quickly being replaced by her being mounted and bred by stallions as her nipples migrated down towards her stomach as her internal organs began to move and change, her pussy getting larger and more accomadating to the growing horse cock inside her.
Cole meanwhile was filling his filly's body with his cock more and more with each thrust. What started out as seven inches when he was human was now growing out into a massive shaft as he grew the shaggier fur and bulkier body of a Clydesdale. He adjusted himself unconsciously as the changes in their bodies forced him forward as he mounted her like a true stallion. He snorted as his face began to push out and his hair became longer and ran down his neck. This was his filly and he was going to breed her, his animal urges overriding any human thoughts.
"So... hot... must... breed..." Cole said through his changing mouth as his cock bottomed out, pressing against her womb as his balls slapped against her newly grown teats.
"Breed... breed..." Kelly moaned as she felt his cock fill her, she knew that no human would ever satisfy her again as she was fucked from behind by this stud. Her fingers and toes fused together into hooves as her face pushed out into a horse muzzle, her eyes migrating to the sides of her face as she did. "BREEEED MEIIIIIIIIIIIIIGH!"
As the last human words turned into a neigh, the bed cracked under the weight of the two horses. Cole thrust into her one last time as her pussy clamped down on his cock, he came hard filling her waiting womb with his seed as their changes finished. Where once there was a pair of human lovers now stood a Clydesdale Stallion and a roan colored mare. Cole pulled himself off her, looking confused at the broken remains of the bed while Kelly nickered, swishing her tail a bit.
Something felt wrong to the two horses, like they weren't supposed to be here. Kelly pulled herself up out of the remains of the bed and looked around, why was she here and not home in her pasture?