Wow, this topic really hits home for me, because for the last few months, I've been dating a girl. Of course, somehow, that changes everything with my friends and even with my family. When I had a bf, it was no big deal and my folks trusted us enough to do the right thing that they'd let us be in my room with the door closed, and he was allowed to sleep over.
Now that I'm with a girl, the rules are suddenly different. For a while, she wasn't allowed in the house unless my dad or stepmom was home. Then it went to her not being allowed in the house at all, even if my folks were home (there's actually a reason for that but I'm not ready to discuss it yet), now she can come over, but she can only be downstairs and my parents have to know what we're doing at all times.
My friends are pretty much weirded out by the whole thing too, and I won't even get into the way her mom reacted to the news that her daughter was with a gay guy. Let's just say it was something along the lines of a warning about AIDS and some other bullcrap. So I definitely voted that it's harder for someone who isn't 100% one way or the other, especially if they've already outed themselves to everyone they know and love.