Right to decide

My ex has decided that at 12, our oldest is old enough to decide whose house he wants to be at when without asking permission - meaning, on a day by day basis. This strikes me as preposterous, but this is the advice he is giving my son. Would this be considered contempt, given that this is NOT the custody arrangement we have in place? Also, at what age can a minor petition the court to seek a change of custody?

I should add that his school bus goes to/from both houses, so he is logistically capable of getting between them on his own, at least on weekdays.

Your ex must follow the schedule in your custody agreement. Your child does not get to dictate the schedule. Judges can consider the wants of a child, I don’t know at what age this is viable, and I’m sure they take many factors into account.

Yes, both parties are supposed to follow the custody order in place. If your spouse is not abiding by it, you could file a motion for contempt or if the arrangement is in an agreement, you could file a child custody claim. There are no set rules about when a child gets to decide where he lives or if he visits, and if you have strong concerns about the arrangement, the court will take that into consideration.