He wanted to try sex as a woman

Joan felt her own penis getting even more erect than it already was. It fully lifted her skirt up. But not only that showed how much she got aroused by the idea of having a long and thick cock up her ass making her cum. Even her nipples got erect poking through her top. And she even bite her lips like a woman would do in that situation. "Perhaps you are right, Dr. Valentine." She said subconsciously trying to speak in a higher, more feminine voice. "Perhaps I always wanted to be a woman and get fucked."

"There is only one way to find out." Dr. Valentine said with a big smile.

"There is only one way to find out." Joan repeated also with a smile.