You guys are talking about history of social norms and I am talking about law. Either allow gays to get married or get government out of ALL marriages. Since the law document of a marriage wont go away, then the right thing, the constitutional thing is EQUAL PROTECTION UNDER THE LAW.
To not allow gays to get married is to treat a fellow citizen as second class.
To not allow gays to get married is to treat a fellow citizen as second class.