Stepmother does not have visitation rights. Step-parents are not custodial parents unless the court has so ordered. Here, you cannot refuse your children go to his home if the divorce decree indicates he has visitation rights and the home is out of state and was out of state when the decree was entered.  However, and this is a big however, if he would not see the children because he works when they visit or the out of state status did not exist at the time the decree is entered, you need to immediately seek a modification of the visitation and custody terms.