The politically correct way to say that something is "gay", especially in a liberal environment where people easily catch feelings. Not to be confused with homosexual. Derived from the movie "Brokeback Mountain." BBM is an acronym similar to JK, ROFL, LMFAO, and TTYL. Brokeback can be used amongst friends, and BBM can be used amongst those who take things too seriously.
"That V-nack shirt is BBM."
"Guys who wear flip flops are totally BBM."