When having doggie style sex with your women. You pull your penis out and whip it against her ass as you ejaculate and growl like a wookie. This could get a laugh or piss her off, only one way to find out.
"So I gave Mandy a wookie whip last night" - person 1
"I fucking hate star wars" - person 2
"Me too. But hey, we got a laugh out of it." - person 1