You don't think, and I'm not saying it does, I'm unsure of the science, sexual attraction works something like taste in food or music?
I think that we can acquire a taste for different kinds of food and music. I believe that sexuality is a little more complex.
I find no evidence that nurture will make a guy gay, it might be the catalyst that pushes his "turn on" button.
Different guys turn out gay or straight at the same rate as the general population even if they are from a nurturing that some thought would "make" a dude gay.
So I think that we are wired into our sexuality with some degree of flexibility. My point in all of this is that I have never heard of anyone
who one day "chose" his sexuality, I think in most cases we discover it, as a 13 year old I found my friend to be attractive to me in a sexual way one day, this surprised me, before this I had messed around with girls and never thought of boys, I even had at least one erotic dream of a girl, that I can still remember.
Did I choose to be attracted to my friend? Hell no! I finally gave in to my desires, this lead me to think (I was a dumb kid) that I had "taught" myself to be gay, for years I thought if I had only resisted the urge, if I had not gave in.
If a guy can "flip a switch", then good for him, most guys can't, again, in a perfect world it wouldn't matter, we would not concern ourselves with what another does.
The world is not perfect, for one to tell the majority "I decided to be gay" is pure bull shit.