When you're making love to a women from behind and she's on all fours. Then you shift up your junk to her ass. She will begin to try to get away using all four limbs.
I gave your sister the fourwheel drive last night. She's a kicker!
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi