If he doesn't put a ring on that finger, I'd get a shotgun and make him do it old-school style. You don't get a GF who loves you that much and not wife her up, keeping her common law would be a travesty, not to mention a foolish thing to do. Like the OP said, she's a keeper, so keep her, and try to make her as happy as you can, a happy and loving wife is a happy and loving life.