What we’ve become inured to is anal sex. It’s pushed constantly upon the public and through porn. The medical effects of it are terrible. It’s called Gay Bowel Syndrome, despite the best efforts of liars to pretend it is a universal problem.
If the anus is a sex organ then anything can be and is. That’s not its biological or evolutionary function. So which is it - nature or God? Either way homosexuality is abnormal, unhealthy and, thankfully, controllable, that is a choice is involved.