The Further Adventures of Super Screw (1975)

The Further Adventures of Super Screw features a nebbish with such a big dick that it drags behind him, gets bitten by a dog, and is run over by a truck. An operation reduces it to a more normal size and, after fucking a nurse, he tries to fuck a gorilla. The gorilla fucks him instead so the guy goes back to the hospital, gets his big dick back, and jams it up the ape’s ass until it pops out of the monkey’s mouth. The End.