This encourages adultery and gold-diggers, at significant emotional and financial risk to the first family. While prohibiting this kind of behaviour is pointless, it should not be encouraged by lessening the risks/increasing the rewards to those threatening existing relationships. How relationship failure between married and not-married people is dealt with should be up to the parties involved, without any legal intervention.
I must admit I was surprised by this. I think he is arguing that divorce shouldn’t have financial regulation by the state unless there are children involved. But he may consider extra marital relationships in a separate category. To me, either these are relationships or not and just because one was officially married or there is more than one relationship going on is beside the point. In any case, like a marital promise, promises made in a extra-marital relationship should not be without cost, should they? What is true is that this law seems like it will discourage people from having more than the socially optimal number of relationships.