Legal Question in Family Law in Wisconsin

Re: can spouse sue husbands girlfriend

Open and notorious adultery is a minor violation of criminal law but that is up to the state to prosecute which is highly unlikely. With regard to a civill cause of action, your chances are extremely slim. You could try a loss of consortiom type cause of action but since your husband is actively participating in the adultery you are unlikely to prevail. If you decide to file a divorce you could always state adultery as the fault count.