You are wrong. A marriage contract is exclusive. Somehow (and it will come out) an adulterer is allowed to remain her guardian. Adultery is against the contract.
Adultery is only illegal against the TWO parties involved.
That would be Terri & Michael. TERRI herself would have to take Michael to court over adultery.
B/c it's NO ONE ELSES BEESWAX.
Plain & simple.