CA-
I am the CP. My son is 3 years old. At the moment I have Physical and Sole custody. When he is about 5 years old and decides he wants to live with NCP would the judge consider that?

Probly not. The child can't decide until he is about 13 years old. Unless you request that he lives with NCP.

CA-
I am the CP. My son is 3 years old. At the moment I have Physical and Sole custody. When he is about 5 years old and decides he wants to live with NCP would the judge consider that?

A 5 year old is not capable of making an adult decision. If there is a motion filed by the NCP to change custody, taking the child's feeling into consideration is a possibility, but a 5 year old could not make that decision. In most states the child has to be at least 12 before thier desires are even used in a modification (even at that age the child does not decide). The judge will decide custody based on the case facts. If both parents agree to a change in custody that decision can be made by the parents as well. The only reason a judge has to be involved is if there is a disagreement and the NCP is filing for modification due to a change in circumstances (he can't just file a modification because he feels like it, he has to have good reason).