Amy felt a twinge above her ass and looked up to see a horse's tail growing, reaching enough size to make your tip touch lightly on the floor. Then her butt changed shape like a horse's and her feet turned to hooves. And finally you hear the latest change, a horsecock with balls to complete growing between her legs. Her new member grew to reach 16 inches length completely hard.
Kiera's desire at this time was so intense that she took Amy's new member and, stimulating the entire length she reached with her hands, she began to kiss the tip. She tried to put the cock in her mouth, but it was too big and she failed.
Amy started playing with her new breasts while Kiera worked with her new cock. She realized her nipples were more sensitive now, which just added the most pleasure to what she was feeling and making her dick even harder.
Before long Amy came. Kiera tried to swallow as much of Amy's seed as she could, but it was too much for her and ended up letting out a lot.
Kiera also had an orgasm, which she found odd because she had never had an orgasm without touching herself before.
After they recovered, Kiera decided to examine Amy's new body. Looking at her from behind, Amy lifted her tail so Kiera could see better what it looked like. So Kiera commented "Actually the underside of your body, except the for the lack of fur, is like a horse's. But I thought your cock had replaced your vagina, but she's still here, ok, but now it looks like a horse's vagina."