Is there anything I can do to stop my husband from giving money to his girlfriend

He has a right to give money to others unless you can show it was obtained by her fraudulently. Your move is to protect the money or give it back, and get a divorce. If he is going to put you and your family at risk, then it seems you have no other choice but to protect yourself. Get into a lawyer's office immediately. As of right now you have no action against the girlfriend, she is entiitled to accepts gifts. You can however in the divorce require as part of your action force your husband to return the money. Good luck.

NC is one of the few states that still recognize an action called "alienation of affections" (AA). AA is a tort action brought by a deserted spouse against a third party alleged to be responsible for the failure of the marriage. If I remember correctly, NC was the state where an AA action within the last year resulted in a verdict against the alleged lover for over several hundred thousand dollars. If the "very young married girlfriend" has no money, you likely will not be collecting any from her. However, some people sue just to get satisfaction in suing. If you and your husband still believe that your marriage is able to be saved, you two should look into doing so. You may want to review your facts and options with an attorney.