I had an incredible idea

Sin should create a marriage system where people can get married and one person from the couple has a baby. Then, if the marriage doesn't work out and the couple separates, the person who didn't carry the pregnancy would have to pay child support to the one who did carry the baby! The child support should be 33% of all the coins the "father" of the baby has + 33% of all earnings in the next 7 days!