You are
fucking doggie style. You pull out,
jizz on the asshole, pee on top of the
jizz, then you let him/her fart and spray it all over you.
You- "Dude, I was
fucking this
chic last night and I jizzed on her asshole and covered it in piss!".
friend- "What'd she do bro?"
You- "She farted
on me man!?!?!?"
friend- "Bro, you got skunked!!"