deceptibro
a bro who hides his true nature during the majority of the day with intelligent conversations, an appreciation of the arts, a lack of alcohol, or anything off putting of a bro; but at the appropriate time, can emerge from his deceptive shell to let his true bro form shine.
"Did you know that Steve loves to party? I mean he usually is talking about the global economy and Bach. I never thought he could bro out."
"That's because he's a deceptibro."
"That's because he's a deceptibro."