An informal term to describe when a man puts his penis into a woman's anus whilst making a dinosaur-like shape with his hand, leaving his index or middle finger out which goes in and out of her vagina in the same motion as his penis.
Can also be: Binary Bang, Binary Banging,
Guy1: So what'd you do yesterday?
Guy 2: I just Binary Banged my girlfriend, bro!
Guy 1: Dude, that's awesome! Imma do that with my girlfriend too!
Guy 2: Cool man!