The Chewbacca occurs when you are having sex with a girl, and, in the heat of passion, you pull her arms out of their sockets.
"What the fuck, Jason, why are there two human arms in your bathtub?"
"Oh, I pulled The Chewbacca last night. Damn shame, third time this year. Sprinkle some more lye over those things while you're in there, by the way. "
this is an act which requires many steps. the first step is to shave your pubic region before sex and place it in a small baggy. the second step, after sex, you ejaculate on the womans face, then throw the pubic hair on so it sticks then put your testicles in her mouth and punch her in the stomach so she makes the gargling noise and the hair on her face makes The Chewbacca
Now I have a rash from shaving my pubes from The Chewbacca