If so, what kind of choices?
Probably the choice to emulate the positive marriages of my parents and grandparents, aunts and uncles.
I'd wager that a child decides that, well before he experiences any sexual desires.
How old are kids when they start "playing house?"
If the immediate and extended family has positively modeled true marriage, if the child has been raised to value family, recognize and respect authority, and base his actions on his determinations of right and wrong (
as opposed to determining right and wrong, based on his own actions), all by the age of reason (probably age 7 years - adolescence), then by the time sexual desires arise, homosexuality has already been precluded.
Truthfully, if I was brought up to value homosexuality (I'm looking at you, Ancient Greece), I probably would engage in it. A disgusting thought, but can any of us confidently and sincerely claim otherwise?
Could anyone honestly say that every man in Classical-Era Athens had the "bisexual gene?" No way. They were just taught (as children) to value that type of sexual relationship, and to pass that value on to children.
It's not in the DNA. It's in the culture.