Can my ex get visitation after he gave them up?

Yes the father can file a motion with the court and ask for visitation. But he will also have to pay child support if he is not already. Unless you have a reason like a protective order against him or child abuse charge against him he will be able to get visitation. You could appear in court and see if the judge will give limited visitations until you feel the child is comforiable around his father. His girlfriend herself has know say what so ever in any decitions made just the father. You can also file before he does giving him limited visitations or supervised visitations until you feel comforiable. But remember some time down the road he will be able to get visitations on a more premanent basis.

As far as I know once a parent has given up thier rights to a child you are no longer required to let them see the child. and the fact that he is locked up should only strength your case.