Then you get the representative payee changed.
"Changes to report
You need to tell Social Security about any changes that may affect benefit payments. As payee, you are responsible for repaying money you received on behalf of the beneficiary if any of the events listed below occur and you do not report them. For example, tell us if:
* The beneficiary moves;
* The beneficiary starts or stops working, no matter how little the amount of earnings;
* A disabled beneficiary’s medical condition improves;
* The beneficiary starts receiving another government benefit, or the amount of the benefit changes;
* The beneficiary will be outside the United States for 30 days or more;
* The beneficiary is imprisoned for a crime that carries a sentence of more than one month;
* The beneficiary is committed to an institution by court order for a crime committed because of a mental impairment;
* Custody of a child beneficiary changes or a child is adopted;
* The beneficiary is a stepchild, and the parents divorce;
* The beneficiary gets married;
* The beneficiary no longer needs a payee; or
* The beneficiary dies.
You must also tell us if:
* You are no longer responsible for the beneficiary;
* You move;
* You no longer wish to be payee;
* You are convicted of a felony; or
* You are violating a condition of your probation or parole imposed under federal or state law.
If you stop being a payee
If you will no longer be the payee, you must notify Social Security immediately. This is important because a new payee will have to be selected as soon as possible. When you are no longer responsible for the beneficiary, you must return any benefits, including interest and cash on hand, to Social Security. The funds will then be reissued to the beneficiary or to a new payee. "
http://www.socialsecurity.gov/pubs/10076.html