On Homosexuality And It's Naturalness

Time and time again I hear the same argument from people about homosexuals.

"It just doesn't seem right. It's not 'natural'. How would we have gotten here if everyone was gay?"

This argument is really bad.

For example...condom use is a relatively recent phenomenon (apparently they were first invented 400 years ago). Everyone uses condoms and other forms of contraception because they don't want a billion kids running around. But condoms aren't "natural" either. They are preventing a male's sperm from entering a woman to continue our species. If everyone used condoms or other contraceptives (correctly) then we would have no more kids.

You end up at the same question, "How would we have gotten here if everyone used contraceptives?"

The point is, just because something is not "natural" means nothing to whether it is a morally permissible or "correct" action. Obviously there are other arguments against homosexuality (all of which are equally bad), but the next time someone tells you homosexuality is not natural, just slap for me please.