Unfortunately for your fiance' the Social Security Adminsitration can hold him responsible for monies improperly paid him yet spent by his mother when he was under the age of 18 even if he never saw the money. The reason is that he was the person for whom the benefits were paid out for. Potentially the money was used for his upkeep and maintenance.The best way for him to try and resolve the situation with respect to owed money by him to the Social Security Administration is to speak with his mother with respect to the possibility of both of them making payments to pay off the amounts that need to be reimbursed.