My ex and I have shared custody. My ex has primary residential custody. Now that our boys are 16 and 17 years old he is willing for them to come live with me from now on. Is there a form I need him to sign that he is giving me residential custody of my boys. And I am paying child support. When they come to live with me do I have to petition the court to stop child support payments. Do I have to wait for them to move in with me or can I do this right away. They want to move in asap.