A game designed to cause public humiliation by vocalizing a desire to rape Professor Snape in his favorite sexual position which was unanimously voted to be doggie style. When a person sees a friend across campus unaware of their presence they yell Snape rape! As loud as they can. The friend yells Snape rape back as loud as they can to confirm they know the first person is there. Lots of onlookers then gawk at the pair for vocalizing such a weird request in public as a greeting.
Girl 1: Snape Rape!
Girl 2: Snape Rape! I called it first.