The age of consent here varies depending on the state, usually between 16 and 18 but there can be all kinds of exceptions and conditions placed upon it too (if the people involved are younger but close in age, for example, or if one of them is in a position of authority or power over the other). But you are right, even if it was a consensual relationship and totally legal, he'll still be vilified for it. And in a way that he would not be if he were female, even. And that's just pathetic. Of course people with big age differences, gay or not, can have healthy relationships. But my attitude has always been that consenting adults can do whatever the hell they want provided that there is no abuse, coercion, etc., as you say.