Ever

Marty had thought that he wanted a woman's body, and he developed a rather elaborate machine to steal the body of one of his co-workers. When he finally got the guts to activate the device, he was pleased with the results. He loved feeling so sexy, but he soon learned that being a woman wasn't so easy. He struggled on the high heels that he had to wear to work, washing his long hair was a pain, and getting his monthly visitor for the first time was simply not a good experience. It wasn't long before he pleaded with his old body to let him back into his apartment to use the machine to swap back. She made him get down on his knees and beg, which he quickly did. Marty was getting desperate, but she only bent down to tell him that he wasn't getting his body back ever...