When is it enough for a parent to help an adult child financially?

My husband and I have been married less than a year and in that time, his so has borrowed money from him and promised to pay it back and never does. Now we find out that he is may need to file bankruptcy. We both are trying to decide what is going on. I explained to my husband that helping him only keeps him infantile and unable to handle his financial matters like an adult.
We also believe this his wife is the same way financially. I know he loves his son, but I have asked him in a very kind way to let him go and make mistakes and grow up. He is only keeping him hanging on to his coat when he gets into trouble. I am open for suggestions...