I wore an earring and no one ever assumed that I was gay. Of course, I wore it on the left ear. If you wear it on the right ear, that's usually considered an indicator that you "play for the other team".
I honestly have no idea why people don't like guys to have pierced ears but I think its hot ;) xD I like guys with pierced ears as long as it fits them and if they gauge their ears, Im fine with it as long as its not too big. Too big is too much for me >~<