Now, itís also true that "Not every time a man has sex with another man will they get AIDS. It does, however, significantly increase their chances, and it is more likely than if they do NOT engage in sex with men." [That is, if instead they only engage in sex with women.]
This is largely true for the simple reason that there is a much higher incidence of HIV in the population of "men who have sex with men." The odds are higher that the person you're having sex with is infected. Men who have sex with other men need to be especially cautious, because they're in a high risk group.