My Husband found out his ex wife who remarried 6 years ago to someone else has been living with someone for the past 2 years is still married to the second Husband. Is this legal? If it is WHY and HOW? He does not want his kids in this kind of situation. What can he do?
The technical answer is "yes, it is legal" - she is not violating any laws that are regularly enforced (adultry is still illegal, but it has not been prosecuted in years)
From a family law aspect, it's clear that the mother is not acting in the best interests of the children. This is a reason to modify the parenting arrangement. A Petition to Modify Custody should be filed in the county where the children are currently living (the residence of the defendant) and perhaps even ask for a Guardian ad Litem. Judges do not like this sort of situation, and it may well also be in violation of the Final Judgment and Decree of divorce.
One side question, and I dont mean to sound offensive, but why did it take two years for your husband to find out? If he does not have regular contact with the kids or his ex, it may be difficult to prove that he is the better parent for the kids.
I wish you the best of luck. Should you have any further concerns, feel free to contact me email@example.com