Bro-tension is a social phenomenon that occurs when two bros interact, but one or both are mad or bitter about the past (usually about another bro), resulting in passive-aggressive behavior. While hugging it out could relieve the bro-tension, it usually never happens.
"Dude, whats going on between Dwight and Antonio? They don't really talk to each other anymore."
"I dunno, man. They've been fighting about which one of them is Kevin's true best friend."
"Ahh, its that bro-tension."