Son

There is only one solution and that is to stop giving him money. Ideally it should be a family decision, given to him formally in an email or similar - and then you should all stick to it.

Give him details of debt managemnt services and budget planning help. The two often go together - and then stick withit.

he will, of course try to emotionally blackmail you by telling you the children will suffer, but just ignore it. By the way, does his wife work or do anything to try and alleviate the situation?

You are not a failure. You have other children who are responsible and careful. When a child is born it is born with a random selection of genes inherited from both parents. Most times we produce children who reflect us in being a mix of good and bad, but sometimes the mix is all good and you get heros and heroines who excel in everything they do and sometime you get a child that gets the less helpful genes that makes them be like your son. I am sure it is nature not nurture that makes him as he is.

So stop blaming yourself. That is not good or helpful. Set your own firm stand against giving him money, even if he tries emotional blackmail and if the rest of the family get on board so much the better. He will be forced to resolve his own financial problems.

Although, I do wonder what support he is getting from his wife in particular and what the reaction of her family is to this problem.