If I were you I personally would avoid it unless I fell in love with a dude, but then again I don't know your parents so they might be cool either way. It's not like you're gay and know that you're going to end up with a guy. In my own personal situation I have no more desire to tell them that I like cock than to tell them how much I love eating girls out, fucking them from the back, being dominated by a hot lady or like watching other guys do my girl. Then again I pretty much don't think I'm capable of really falling for another guy in the first place (societal prejudices or not), so I might not be the one to ask.