Inmates in the federal pen show that sexual interest is a little more fluid than you indicate. Also if your mom’s boyfriend started sneaking into your room when you were 5 it might alter what happens when you are 11.
Both of what you say is true. Some things can sway or override the sexual preference. But not your innate preference. I knew a lot of men abused by authority figure men when young, who are 100% straight, never mind what happened to them. Childhood abuse messed them up, but they never turned gay. Drug addicts sometimes engage in same sex to get $ for drugs. They would literally “do anything.” And some men get so horny in prison they would accept a man servicing them and pretend it is a woman. Again, not gay.