I agree with Sassy, so what if it is unnatural? And who is the person who decides that it is unnatural? If it is unnatural, why does that mean that gay people shouldn't get married? What about chemical burns victims or people disfigured in an accident, should they not legally allowed to be married too.
What does unnatural even mean when it comes to now? We are all unnatural, doing unnatural things every single day.
But it is still really offensive to refer to people as being unnatural. We are all people, we are all equal. Time the laws reflected that.