Bigmo I am repeating again. I am not a tyrant. Beating my husband and forcing him to stay with me afterwards is silly. Let him go his way. He doesn't love me that's why he committed adultery. And what about fornication? What's wrong with that if the partners consent? Even as a Muslim I didn't find anything wrong with that. Sex is one of the greatest expressions of love. You just have to do it safe.
I think we sometimes need to think of society as a whole at times.
1. Just because someone commits adultery does not mean they don't love you. It might be totally unacceptable for you and thus the marriage should end. It might be that the adulterer is horny, has low self-control, doesn't associate sex with love as much as yourself...
2. Marriage is fundamentally a social contract. All social contracts need to be enforced. Otherwise what is the point of marriage? Why even have it? Why have rules about it if it needs to end. Every society develops some kind of rules on sexuality/family because that is what we spend most of our time doing. Social rules have a purpose. They might not seem all that valid today, but in their time it probably was. Life was pretty harsh back in the day. Just trying to eat enough and not get robbed, killed, enslaved... was probably a luxury.
Maybe the family unit was for the 'greater good' and so it was both socially and legally enforced. Kids got a home, taken care of, raised... Having such strict rules against adultery might have decreased violence as well. Again life was much harsher back then. Heck, rules against massive polygamy might be said to also decrease violence as you have more men with a family, instead of roaming in packs.
I'm a very libertarian minded person, but I think we do need to recognize society exists. These rules existed for a reason. They might not be valid anymore, especially since our material needs are decreased and we have increased order from government. But there are still lessons there.
Do we have any idea what a society of free sex and not based on the family unit will look like?
I sure don't. It might be a good transformation. It might not. But it's not as simple as being individuals and doing what we want. Social rules exist. legal rules also exist.
My own personal view is that while we have liberated ourselves of many oppressive legal rules, there is definite historical wisdom in social rules. They can and should change, but I'm pretty careful about it.