Nobody chooses and it's not genetic. It's determined in a raffle in 3rd grade. I thought everyone knew that?
They march all the 3rd graders (in perfect little lines) down to the gym every October. Then they have a sexuality raffle. If they call your number and the wheel of desire turns to one of the "you're gay" sections you're gay. If it turns to one of the "hetero" sections you're straight". One kid in every school winds up on the "you're just a sick fuck" section too. That's the kid that winds up liking pets as more than just friends.
i knew a kid in 3rd grade who always played with the girls at recess. he even owned two Cabbage Patch Dolls that he brought to school so the other girls and him would play with them at recess.
I was kinda like that when I was a kid. Without the dolls though. & I played cops & robbers type stuff. I was just scoping out the territory.
I have a Brother in Law who is gay. Other Brother in Law & Wife are straight as arrows. They said they knew from when he was little there was something different about him.
I think it may be either genetic, or something to do with foetal developement.