Gays have married opposite sex people throughout history. I’ve resently read an article about a lesbian and a gay man happily married for over 30 years.Thats not the argument. They are being denied marriage to the person they desire to be married to, who is otherwise also legally capable of being married.
If gays want to opt out, that’s completely ok.
And, OBTW, do you have any idea how many lesbians I’ve slept with over years? And I’m a straight man.