How old does the child have to be to decide for themselves which parnet he or she wants to live with? And is this something you would have to go back to court with?
There is no set age, 18 is the only age where the parents and courts have no control. In most states, as long as the child is at least 12, their opinion of what they want will be considered but the courts do not have to listen. It still has to be in the childs best interest.