Michelle Obama tweets birthday love to 'greyer' Barack

 President Barack Obama, second from right, leaves Andrews Air Force Base, Maryland, for a weekend in Camp David, Maryland, Saturday, Aug 3, 2013. Michelle Obama took to Twitter on Sunday to send her husband an affectionate birthday message
 President Barack Obama, second from right, leaves Andrews Air Force Base, Maryland, for a weekend in Camp David, Maryland, Saturday, Aug 3, 2013. Michelle Obama took to Twitter on Sunday to send her husband an affectionate birthday message - and a gentle ribbing about the US President's greying hair. -- PHOTO: Ap

WASHINGTON (AFP) - Michelle Obama took to Twitter on Sunday to send her husband an affectionate birthday message - and a gentle ribbing about the US President's greying hair.

"Happy birthday, Barack! Your hair's a little greyer, but I love you more than ever," Michelle Obama wrote on her official twitter account, @FLOTUS.

The message was accompanied by an undated black and white photo of the Obamas as a young couple relaxing on a sofa.

Barack Obama is spending his 52nd birthday weekend at Camp David, the rural Maryland retreat made available to US Presidents. He was to return to Washington later Sunday.