Society may properly use the force of government to regulate PUBLIC BEHAVIORS, but that is ALL. What someone does, either alone or with others who are capable of and do give consent, is NOT the business of you, me or government, period. If that PRIVATE activity spills over into some sort of public arena, then and only then may society allow government to step in and put a stop to the public aspects of it... such as not allowing a person to drink on a public street, fornicate where he or she might scare the women, children and horses, or operate machinery after becoming intoxicated, where there is grave danger to others not otherwise involved in whatever activity has been going on. Or discharging a firearm or weapon in public and it’s not an emergency. Otherwise, the only legitimate recourse YOU have is to either live with the situation... as freedom can sometimes get a little messy... or use your powers of moral suasion to convince your neighbors that their behaviors are not good for them... but initiating force, either personally or through government, to get someone outside yourself and your immediate family to act as YOU think is proper is totally anathema to a free society AND the Constitutional Republic we once had in this nation. In a free society, even PROPOSING such “laws” would be good for a tarring and feathering AT THE LEAST.
Consider a typical single welfare mother raising multiple children via multiple fathers. Is the behavior that produced the children still a completely "private" matter?