If you are divorced and you were awarded the use of the house, then you can authorize anyone else to move in with you.  The only exceptions are:  (1) it can't be someone who would or is a danger to your child and/or (2) it can't be a violation of your parenting order.  If your final order prohibited any overnight guests of the opposite sex to whom you are not married, then you would need to wait until ya'll were married before he moved in-- so as to avoid any issues associated with the rules imposed by the order.