Show me in law where marriage MUST BE based on a cross cultural constraint of evolutionary mating.<quoted text>
Marriage is a cross cultural constraint on evolutionary mating behavior.
Gay couples are not an equal relationship, just like all other relationships, every single one of which is ideally birthed solely by marriage.
Just admit it, you have no logical answer, so you spew out ad homoan attacks.
Show me any jurisdiction in the country that refuses to allow marriage that is not based on a cross cultural constraint of evolutionary mating.