tri-thunktum

Thunking with 3 or more people, basically the dirtiest orgy imaginable.

Chick 1: "Fuck I'm so sore"
Chick 2: "Yeah, that tri-thunktum was nuts! I didn't think it was possible."
Chick 1: "I know! Did you see that guy's *****? How did it get there?"