My granddaughter is a cheerleader in college there are 16 males and 14 of them are gay. She does talk to them about their choice and tries to make them think about it. She also tries to talk to the girls most of whom are promiscuous.
It helps that she is very confident, outgoing and friendly but she is also the youngest on the team but for the most part they respect her opinion because she walks the walk.
Normalcy changes with time
Social isolation is critical to the maintenance of a cult. Members are generally forbidden to have any kind of relationship with outsiders, even friendships. The outreach suggestion was taken as a hostile act against the group. It is an article of faith that members of the opposite sex (unless they themselves are homosexual) are without exception monsters.
So if you can't fight genetics...explain vegans. Humans are genetically designed to eat more than just plants and vegetables, and yet there are many, many humans that defy genetics and do just that.
So if homosexuality is unalterable...explain Anne Heche. She was heterosexual, then lesbian, and now once again heterosexual.
To borrow a line from "The Princess Bride", I don't think those words (genetic/unalterable) mean what you think they mean.