Quite frankly Don, it would not really help anything to tell them.
Only my brothers and my mother know about me... My father don't and i won't tell him. If he asks me, i'll tell him yes i am gay... but if he doesn't ask, then he won't know and that's fine with me

It's my own business, i'm not hiding it nor shoving it in people's face

In your case, you said your parents were very homophobic... what could happen if you tell them? Maybe open their eyes and be more open about the issue or make them uncomfortable and even make them sick so quite frankly, i would not say anything... if i felt that there would be a chance that it might hurt my parents, then i would never even try to tell them. Just my 2 cents.