"Any sexual behavior outside of heterosexual behavior is disordered. It is biologically wrong as procreation cannot result."
I don't see why nature's "intentions" (which in itself ascribes anthropomorphic characteristics to nature) should matter at all when making moral judgements on actions. Many people do plenty of things at odds with their biological imperatives every day, and there's nothing necessarily wrong with that. "Natural law" is nothing more than one big "is=ought" fallacy.