But whether you're attracted to brunette men or brunette women is genetic.
But what if you fantasize about brunettes (for example), but you only date blondes?
You're a playah!
I have no idea about genetics. I do think it's funny though that people will say it's a choice for everyone and yet if you asked them if they are consciously choosing to only be attracted to their opposite gender or if they could choose to be attracted to their own gender they will deny it. I am NOT saying anyone in this thread does so, it's just an easy way to flip it round when people say it's a choice. Our hardwiring is often so hardlwired we don't see it, we just notice wiring in other people that seems glaringly different to our own.
I also think some of us are so bi or pan or fluid or whatever word you want to use that we can choose to pursue one of our many preferences over others, for whatever reason. But the majority of people don't have that.