Diane's body ached all over. Her feet were the next thing to change. She'd flung her now too small shoes across the room in frustration, and then flung herself onto the couch. She screamed in pain as her balls were pinned against her inner thigh.
"Dammit! Why is this happening to me!?" she cried. Her voice was more of a whinny, but she didn't care. The pain in her body was overwhelming her. Her penis kept sliding out of its sheath, and her balls were started to get awfully heavy and full. The pulled down, and were being held in a painful manner. Diane tears her pants from her body, and sighs in relief as her balls are left to hang free.
She idly scratches them, and enjoys the sensation. Diane's hands slowly stop scratching and start pumping. They move up and around her horse cock. Below, her feet have stopped hurting. But only because they have collapsed on each other. Her toes merged into one large toe, covered in a thick black nail. She had hooves, and she kicked them out as she reached orgasm.
Diane whinnied again, and felt a load travel up her shaft. Her penis exploded with cum, splattering it all over her chest. She looked down, and started gulping up mouthful after mouthful of cum. Her face slowly began to stretch out, until she was able to engulf half of her two foot cock.
When he pulled back, Diane licked her thick lips. Her body was covered in cum, and a new layer of chestnut fur. Her entire chest had flattened out, and her bra hung useless on her chest. Her body had gained even more muscle and mass. Diane ripped her sweatshirt from her body, the collar starting to choke her thickening neck. A line of hair is growing down the back of her neck, and between her shoulder blades.
"That felt so good. But what was I going to do?" Diane thought, her mind becoming a bit foggy.
"Oh, I was going to see Chastity. Wasn't I?"
Diane sat on the couch, her penis hanging down and dripping cum onto the floor. Her chest heaved up and down, ragged breaths from her first male orgasm. Diane tried to form a complete thought, but the only thing on her mind was where she could find mares to mount....