South Carolina Custody Laws......

My sis and her b/f (who is married to someone else, but separated for years) are splitting and they have a 18 month old daughter. My sister wants to move to NC which isnt far but would give her a better chance to provided for her daughter. Her b/f is telling her she is not leaving with his daughter and is not allowed to leave the state. My question is what laws would apply to them...he's married to someone else even if he doesnt want to be. I just don't know how to search for laws that apply to this. Any help would be great! Thank

If there is no court order in place she can move and if he wants to try to stop the move, he can file in court, but it is not likely he will prevail based on these facts.