My boyfriend and his ex girlfrien were never married and have never lived together, he is 21 and she is 19 and they have a 2 year old son, now that she has found out he has started dating me, she refuses to let him see his son. Does anyone know the legal way in NC and what he needs to do first.

Is he on the birth certificate? In either case, he needs to file for custody and visitation in your local Family Court. If he's on the because then there may not be need for paternity tests. The court will establish him as the legal father and he can then ask for joint custody and visitation. The court will either set or help negotiate a visitation scheduled which she will have to adhere to.