One of the challenges of living in a free society is being confronted by things that we don't agree with, or are even repulsed by. That's a problem, but not a legal one. If we say we value freedom, then the criteria to judge the legality of an action, be it gay marriage or otherwise, is this: Is this action harmful to society or the individual? The burden should be on the person who wants this action to be made illegal. It's tempting to codify those actions we find disgusting as illegal but it does nothing to advance freedom and tolerance.