So, from the past few days of chatter, it seems that the question regarding the child is vigorous and ongoing. This thread is NOT about that. Instead, I sense a near-universal agreement that the deceiver partner is clearly in the wrong, that nobody feels much sympathy for them, they should be divorced at the very least, etc.

So then, what is the "fairest" restorative justice the deceived partner should realistically seek/expect? Legally, socially, financially, etc. We can be aspirational if you feel the law hasn't caught up for example, but do try to be realistic: asking for $1b in damages or a branded scarlet letter is probably untenable in contemporary cultures.

You can bring the child into the picture to the extent that it might affect them (ex: some people were arguing that forcing the mother to pay back the deceived father would impoverish the child, or that jailing her would deprive the child of a caretaker), but try to keep the focus on the deceived partner-deceiving partner if possible.