I just saw this on Dr. Phil about "alientation of affection" which is legal in several states. The lady on t.v. was ordered to pay 50K to the "wife". Of course, she was fighting it because she said it was "his" fault because he never told her he was married (they had a long distance relationship). Also, once she dug around, she found out their marriage was in turmoil/lots of counseling before she even came into the picture. In the state of the "wife" though, all of that previous marital stuff didn't matter in court and she was able to sue the third party. I guess it just matters how much of a fight you want to put up.