I had no idea what homosexuality was until I was maybe 16, and then I didn't understand it, at all, probably still don't. BUT, I can't imagine a male "deciding" he likes boys more than girls without some kind of internal urge. Ergo, it's not something a person can control internally, though several of the gays guys I know were married and had kids with women back when, so they "buried" it for a time.
I don't think a heterosexual male can "decide" to be otherwise, except as some kind of mental defect or attention getting device. We've had homosexuality as long as we've had human history, so it seems to be a genetic thing of some sort. And yes, one could argue it should in time "disappear" because of lack of reproduction, I don't know if that's the case, it could be a recessive gene.
I very rarely see a couple in public here displaying any outward sign they are homo or hetero. I admit I don't much care.
