An American fraternal term for a guys' night where they do guy things like drinking beer and talking about girls.
Madeleine: Hey Paul, wanna come over? We can cook and watch a film.
Paul: Hey, sorry can't. It looks like a bro and sack night with my house mates tonight.
Paul: Hey, sorry can't. It looks like a bro and sack night with my house mates tonight.
by madsb October 24, 2009