This one takes three and some acrobatics. You've got penis-haver # 1 in the middle doing the most work. Vagina-haver wraps their legs around the penis-haver, being fucked / fucking. Both should contribute. Seemingly standard stand-up sex. Finally, you have penis-haver # 2 fucking penis-haver # 1 in the ass. Legs also wrapped penis-haver # 1. So if all 3 get their rhythm and thrusting right, it's magical. But requires the right people for sure.
Confused friend: Wait wait wait. So you're saying you were fucking your partner while also being fucked in the ass by some dude? And standing up, supporting both their weight just thrusting into each of them? What the fuck?
Penis-haver # 1: Bro, you haven't lived until you've experienced a bisexual monkey thrust. Trust me.
Ruler of Lake Titicaca. Rumored to have a bunghole that gets very angry if it does not receive toilet paper. Cornholio the Great is often seen walking around with his shirt over his head and his hands in the air, chanting songs about his power, and his bunghole.
"I am Cornholio! You do not want to face the wrath of my bunghole, for I need TP!"
Butthead: Shut up, Beavis! (uh huh huh huh)
Beavis: Um, okay. (heh heh heh heh).