All law is based on someone's morals.
That's just silly. If "somebone's morals" are your criteria for writing law, you'll get all sorts of goofy laws. Heck, the liberals use that as their justification for micromanaging the lives and businesses of everybody else.
I would say that if you're looking for some over-reaching basis, I'd say that all law is based on protection of property, including the property of one's person. The first laws were created to protect the property of the Sultan/Pharaoh/Chieftain/King. Each successive reformation from the Magna Carta to the Constitution extended that protection to more and more citizens.
But that's not really what we're talking about here. There is no impact on either property or person. To the extent it is a crime, it's a victimless crime between consenting adults. There is no Constitutional basis for those laws, and the 14th Amendment makes the validity of these types of laws shaky at best.
This whole issue comes down to a conflict between the rights of individuals and the powers of the state. Given this conflict, and in the absence of an impact on uninvolved parties, I'll take liberty every time. Freedom doesn't mean "the right to make the choices I want you to make."
After all, do we really want the government deciding what kind of sex people should be allowed to have? Is that what conservatism is really all about?