That’s a fine thing, but as far as I know, there is no provision in the Constitution or the Bill of Rights that bars the states from making laws regarding sexual morality. The Supremes effectively pulled Lawrence v. Texas out of their collective ass, so to speak.
Supreme Court views homosexuals the same as straight people. And you can’t create laws that impact homosexuals differently than heterosexuals. (equal protection clause)
Yes the states can outlaw deviant sexual behaviors (ie: pedophilia, bestiality, etc). Children and animals cannot consent. But homosexuality is only considered “deviant” by religious texts. You are still dealing with two consenting adults performing sexual activities within their own private residences. You can’t outlaw that according to SCOTUS.
We can argue about it all we want. But that’s the court’s interpretation.