An insult, although not meant to disparage actual gay people. It is a pheneomenon in which a heterosexual
man unsuccessfully attempts to woo a woman and winds up being an intimate but wholly platonic friend instead. The
man naively believes that if he just sticks around long enough, and shows the woman his sincerity, a romantic relationship
will eventually develop. In actuality, this
will never, ever happen. Hence the
man is the "de-facto
gay friend." One can also be a "post-relationship
gay friend." In this situation, a romantic relationship ends, but the woman says, "let's be friends; I still want you to be my best friend." The man, somewhat pathetically, agrees to this proposal because of confusion, cowardice, or simple foolishness.