Besides being chased by an angry spouse wielding a golf club, adultery now carries another danger: lawyers.
The next time a married man or woman glances your way, you might think twice before acting on impulse and frolicking between satin sheets. The scorned spouse could sue you.
Yes, you read that right. You, the paramour, can get hit with a lawsuit that could cost you hundreds of thousands of dollars.
They're known as "alienation of affection" suits, when an "outsider" interferes in a marriage. The suits are allowed in seven states: Hawaii, Illinois, Mississippi, New Mexico, North Carolina, South Dakota and Utah.
The law allowing such legal action dates back to antiquated times when a wife was considered the property of a husband. A broken-hearted hubby could go after his wife's lover -- not with a gun, but with the law.
Wayne Drash of CNN has more on the "alienation of affection" lawsuits: Link
The big reason is causation- you shouldn't be able to sue a third party for the actions of your spouse.
The articles below are accurate, in my view:
http://www.answers.com/topic/alienation-of-affection
It's kind of like in Muslim countries when the woman is killed when she sleeps with a man that is not her husband.