The point in a conversation with male friends where all talk turns to sports and you couldn't really give a fuck.
You're eating at lunch and asking how a person is doing, and someone mentions the local sports team and for the rest of the time, all that is referenced is the game from the night before. At this point in the conversation, you are in "bro-man's land." This is a play on "no-man's land" if you are that dense. It was the area between opposing sides on the battlefield in WWI where few ventured, and fewer survived.