snake in the gutter
When a man sticks his flaccid penis downward between a women's butt cheeks and proceeds to urinate down her butt crack and legs, using them like a gutter for his yellow rain.
"I can't believe it, George stuck his penis between my butt cheeks and pee'd!"
"Wow, sounds like he pulled a snake in the gutter on you."
"Wow, sounds like he pulled a snake in the gutter on you."