Nope, your 14 year old son cannot choose which parent to live with. If the case went to court, your son's preference for where he wants to live would be one of the factors the court would consider, but not the only one. So, no, your son can't choose which parent.
You will want to talk with an attorney about your situation.
Sign up to receive a 3-part series of useful information and advice about child custody law.