the government has no business in marriage,,,
True enough. Most weddings are in a church or chapel anyways, and the congregation witnesses a commitment before God and His people.
The divorces are the hard part. The child custody, support, and alimony.
Otherwise it's prostitution on the street, but the worst side effect of that is that their desire to steal becomes too strong on the street, sex or no sex, which is why the Bible says "Thou shalt not covet" whether it's another man's wife or property, position, goods, whatnot.