If a man has sex with a man that is gay sex, there doesn't need to be a finer level of distinguishing to this. It's not good or bad or better/worse to be any kind of orientation, and in today's standard English language, sex between two people of the same sex is gay.
It is gay gays gayly gaying around with gays.
Lord give me strength "men who have sex with men". And I've seen people complain about pidgeon holing? what the hell is "MGM vs gay", fucking.... sparrow holing?
The correct answer is, without Judge Judy having to stop for even a moment to hear any more of the case "there is no difference; Men who have sen with men are, along with whatever else they are, gay as well, for they have gay sex".