I've heard about it but I dunno. My family would be a good example on my dad's side which is what made me wonder about it. Me and my dad's family have all grown up and live in significantly different lifestyles and haven't really had contact with each other (so it's not like we influenced each other). My dad, my aunt (his sister) and I for an example are all bisexual. I didn't grow up with my dad or my aunt and my dad left home when he was 16 so he didn't grow up with his sister for the most part either. So is there such a thing as a gay/bi gene?