A Couple Is Arguing, and Then the Guy Head-Butts a Store Window

Somebody posted cell phone video of a guy who's arguing with his girlfriend on a busy city sidewalk.  It was St. Patrick's Day, if that matters.  Anyway, he gets so frustrated that he suddenly runs straight AT a store window and head-butts it. 

It shakes him up for a second and he falls to the pavement . . . but he gets back up and tries to reason with her as she walks away.