A "from behind" sexual position. A kind of modified doggy style in which the male penetrates from behind, but is crouching over the female while standing with his feet up by the females knees. Similar to "monkey fucking", except ape fucking is more vigorous, with the male clutching either handfulls of the females hair, or gripping the females neck. Can be used in either vaginal or anal sex.
Last night was the first time in weeks my girlfriend has given me ass, so I decided to ape fuck her. I probably won't be getting any for a while again now.