As Jen pounded her lover with all she had, she felt a growing pressure inside her, a deep need that had to be fulfilled at all costs. She needed to cum, but her body wouldn't let her; her cum needed to be saved for corrupting other girls. Jen's inability to blow her load only drove her to try even harder; it was in her nature to not let anyone or anything stop her from getting what she wanted. Her whinnies were full of lust and rage. Each thrust was stronger and harder than the last. With each push Jen could feel herself inching ever closer to the edge.
Jen's whole body shook, and she felt her nubs hardening inside of Kylie. A powerful orgasm washed over her body; she had broke through. Her balls began to churn, contracting and expanding as they prepared to release her load. Kylie could feel the pressure building up inside of her and was excited that Jen was about to cum in her again. She clopped her hooves against the ground impatiently as she waited for the load of corruptive goo. After just a moment, Kylie got exactly what she was waiting for, and whinnied in delight as her womb was filled with Jen's cream. It felt so good inside of her, hot and... sweet?
Kylie gasped as something in her pussy wrapped around Jen's cock. She could feel lips blossoming from her honeypot. It seemed her moist cunt was becoming a lower mouth. Kylie used her new mouth to suck Jen off as hard as she could. Her hooves clove and the four segments that formed extended into thick fingers like those on her hands. Her legs shifted and cracked, bones popping and muscles rearranging themselves; they became a lower set of arms attached to her hips. Kylie groaned in delight as she felt herself changing. She loved being corrupted and corrupting. It felt so dirty, but the dirty-ness was what made it so good.
Her neck extended out and up, up, until it was at Jen's height, even while Kylie was on all fours. It kept going, and soon it was even higher than Jen. New ribs sprouted from her spine below her head, and bumps appeared at the sides of her newly formed torso. The bumps stretched out, filling with thick, dense cords of muscle. They bent, and continued for about the same distance before stopping again, and shifting into palms, which split into four black digits. She had a set of arms underneath her head again. Her upper body was nearly complete, but it was missing a very important feature. Two growths appeared on her chest and began to expand. They filled with fat until they sagged. It was quite clear that they were breasts, and large ones at that. Kylie moaned as the tips of them writhed into long nipples, which almost seemed like short tentacles, being about half a foot in length.
More budding breasts slowly bloomed underneath the first row. Soon the front of her body was lined with them, and her underside began to develop them as well. The rows of tit-flesh continued all the way down to her cock, which stirred into action, mutating further. Her nubs became more like nozzles, and they dripped with copious amounts of lubricating pre-cum. Kylie panted as she finished changing, She was definitely a bit larger, and stronger than Jen now.
Kylie grunted, her tentacle nipples vibrating and extending until they reached an appreciable length. They twisted backwards, coiling around Jen's body. Kylie neighed delightedly as she pleasured herself against Jen's soft fur. Kylie pulled Jen out from herself and lowered her down, underneath her body. With her tentacles she pulled Jen over her cock. Both of them whinnied in pleasure, and from her elongated nipples, Kylie spurted hot creamy milk across Jen's fur.