So you are still in favor of government interference in these private decisions. Thought so.
I would hazard a guess that the majority of murders are done privately, but I advocate none of them.
We have some very intelligent contract law here: contracts signed by minors are unenforceable, as an example. We also have some very ignorant contract law: no-fault divorce has wreaked absolute havoc on the American Family, particularly on men. "Marriage" and "divorce" have historically been the realm of the church, secular authorities only intervened when it became somewhat necessary to give some form of legal recognition to the thousands of bastard children that were being birthed by unmarried (and apparently non-church-going) couples, hence "common law marriage."
A light aside, if I might: the state of Ohio, just a couple years ago, became one of the only states to actually annul a long-standing common law - that of "common law marriage." Most of the states, and definitely the FedGov, pretend common law doesn't exist anymore, although it is actually still in effect where not properly annullled or amended...