What law? I've never seen such a law. And certainly not in Kentucky, which has laws prohibiting marriage between members of the same sex.
In our system of government, it’s been established for over two hundred years that any law held to conflict with the Constitution by the Supreme Court is invalid. Laws limiting marriage to man/woman as opposed to woman/woman and man/man have been ruled by the Supreme Court to be in conflict with the Constitution, therefore they are invalid.