I got my ex wife to pee during sex. Things had stalled in our sex life and being that I have a pee fetish casually said during sex once, "you know I hear its kinda erotic to pee during sex". She was surprised by this but she said well I gotta go, so here you go. Next thing I know my dick is getting soaked in pee. I came HARD!
Thats as close to a GS as I have come.