General Discussion

Its based on "alienation of affection". If you can prove that someone made your spouse not want to be with you anymore, you can sue them. There was a case in 2019 where some guy sued this other guy who had an affair with his wife and was awarded over 8 million dollars. And there definitely was no professional relationship in that case. He just said "he screwed my wife, it destroyed our marriage".

Based on the details I've read about the case, the wife isn't claiming that he was coerced either. She just claims that he was seduced. The truth is, her husband or ex-husband or whatever their status is now, is an asshole who betrayed her. If you are tempted to cheat on your spouse, you should go ahead and get separated. Its obvious that you aren't into the marriage anymore if you no longer want to be with just them and you aren't in some open marriage agreement.

And the whole thing was originally designed around the thinking that your spouse is your property, particularly women being the property of their husbands.

I understand your extreme case and I think there are probably a whole host of other laws that could cover compensation for something that insane. This law wasn't designed to punish an extreme case like that, though it incidentally would work I suppose.