If there are no real problems with the father (abuse, drugs, etc.) then I would think it would be ok to allow the child to meet his father. It may be that his immaturity got in the way earlier, but now, he would be willing to step up and be a real father. Make sure he knows though, that once he's in the child's life, he's there for good. He needs to know that popping in and out of the child's life is not acceptable and that you won't allow it. If he can visit and call the child on a regular basis, then I don't see any harm.