Actually, in our view the abnormality is in irrational discrimination imposed upon homosexuals and codified into federal and state codes. But we are fixing that abnormality state by state.
I can promise you that eventually, the true abnormality will be easily recognized: it will be seen in those that continue to irrationally denigrate homosexuals. You are on the wrong side of history, the wrong side of morality and the wrong side of ethics.
The abnormality is that homosexual behavior is unhygienic and infertile. Biology has a way of dealing with this even if you think there is no God.
No species can survive more than a very small minority engaging in homosexual behavior. It is not "normal" in any sense and there is an instinctive revulsion to homosexual acts in the vast majority of homo sapiens. Children are naturally repulsed by effeminate males and masculine females and have to be brainwashed out of it with "anti-bullying" laws. It's funny how the supposed rationalists always take a big detour around evolution when it's politically incorrect.
Recall too that from the time we let homosexuals out of the closet, it took about 15 years for them to spread a terminal venereal disease through their ranks. Now we deploy costly therapies to keep them alive, walking Petri dishes of antibiotic-resistant bugs. As the anti-retrovirals get ramped up, viruses will surely mutate in response.
To the plague-filled, childless end, this will be touted as the New Normal.