Since we all start out as "females" in the womb, I guess it's possible that some environmental factors can obstruct whatever process is supposed to go on for for a full "conversion" of female -> male. That way you could get an individual that is homosexual, bisexual, hermaphrodite, etc...
What does it mean for a hermaphrodite to be gay? Only attracted to other hermaphrodites? But can they be attracted to either men or women or both, and still be "straight" because those people have a different sex? Or are they gay no matter who they're attracted to? Just asking! ;)