I’ve written about Millie before. Please see [my first post](https://www.reddit.com/r/gonewildstories/comments/7pgbeg/angry_fucking_my_ex_in_the_park_next_to_her_house/) for a description. She was an insanely sexual person. She masturbated constantly and she was into some kinky things. Besides being a little bi, she was very into rape fantasies and incest fantasies.
While she claimed to never be interested in her own family, I started teasing her about her brother, who we will call Stan. Stan was tall and handsome so naturally, being the perv that I am, I fantasized about them fucking. When I shyly told Millie about this she was immediately turned on. She said that it was hot that I would be fantasizing about her doing something so depraved. I’m pretty sure, though, that when I would talk her through these fantasies that she was actually getting off on the idea of sucking Stan’s big cock because he wouldn’t let her borrow his car. When I told her that i imagined the two of them swimming in their parents pool, fake wrestling, and her hand accidentally grabbed his dick, leading him to pull her bottoms off and start pushing his fingers inside of her in broad daylight, she slid her own hand under her pants and made herself cum in less than a minute.