I think if anything is consider it should be in writing between the couples not as a law for all people with in the state. This is something that is a small government idea with power reserved for the people so to speak to place it back in their own hands.
I encourage people to be open about how or what they expect is all. If a person agrees then people can do as they want. I do not like the idea that government can set blanket laws for everyone in these areas but understand that some may feel they want them. So let the couple work them out.