FallDuskTrain raised a valid concern. This young man deserves compassion. I'm sure there is a long story behind how he got to be the way he is. It is obvious to me that he is abysmally immature. He didn't get that way all by himself. Something was severely lacking in how he got reared. Mom needs to take some responsibility for that.

However . . . all that being said . . . I don't think this mother and this 24 year old son will do each other any good, living under the same roof. They will just recreate the dynamics that led to him being how he is. A lot of that is not his fault. But the two of them getting together isn't going to fix anything. There seems to be zero insight on both their parts.

This young man may be permanently damaged. Getting his teeth knocked out in a bar suggests that he has profound issues. He does not know when to leave something alone. He wants to emotionally blackmail his mother into letting him move back home and live as a child forever as how he expects her to make restitution for failing him when he was young.

He is emotionally disturbed. It is obvious to me that he does have mental illness. Maybe a lot of that is his mother's fault. Mom is mentally ill too. She probably didn't get the upbringing she needed from her parents. But history is history, and now is now. He wants to be taken care of by Mom as a right. If he gets back into her house, I think it is all too likely that he will go back to being 15 and that's how it will be for as long as Mom has a house. Mom pretty clearly, and accurately, sees this. I think she honestly does not know what to do. All the contract-writing in the world is not going to make a dent in this situation.

This young man, were he left to wander the streets, would have a better shot at maybe growing up. With Mom, all he will do is regress. He did get through college, so he is not without some inner resources. But he will happily become as big a baby, as circumstances will allow. I don't say that heartlessly. I fully appreciate that he didn't get that way all on his own.

Mom does need to expand the realm of her concern to beyond just not wanting anything to rock her boat. Taking him in may not be the answer. But I don't know how you just let your sister handle your problem child and more or less think: "Better her than me." Mom talks about providing some financial subsidy to assist this son. There may be a constructive way to do that. I would encourage her to get some professional counseling on how to set that up.