A bro-film is the complete opposite of a "Chick-Flick". This is a movie that, instead of being watched with your girlfriend, should be watched with your guy friends, hence "Bro-Film"
Guy 1: Dude have you seen The Notebook?
Guy 2: No, I'd much rather see a Bro-film than a chick-flick.
Guy 1: Oh yeah, like, "I love you, Man"