I am admitted in Georgia.

If I was representing you in your divorce, I would not recommend your moving in with a boyfriend. Until your Georgia divorce is finally entered by the court, you are still married. The boyfriend therefore exposes you to allegations of adultery and more importantly in today's child protective world, you are opening yourself up for allegations of improper conduct that would be easy to allege and amplify in court.

As to the custodial status of the children, your question does not provide enough information. I do not know whether placement with the grandmother has been stipulated to or ordered by the court. Having that information would yield an answer. Otherwise, there are no laws that specify to such a high level of detail what divorcing couples can and cannot do as to housing arrangements with their children. Those determinations are made by the judge on each case.