I don't think is about being gay. Is more of a Gang thing and admiration. In many anime where the boss of the gang talks to someone outside the circle, they bully the outsider. "Who the hell are you and why do you talk to our boss with such familiarity". Little do they know that Jun is a monster on himself, he is the only to keep up with Tomo in a physical level. The other monster being Tomo's dad, that even Tomo has trouble with.
