The 'Sexy Back' singer shares a joke with Lisa Snowdon as the pair continue hosting the Ball. This image appears in the gallery:Justin Timberlake At The Summertime Ball 2013 - Pictures 9. The 'Sexy Back' singer shares a joke with Lisa Snowdon as the pair continue hosting the Ball. Picture: PA 11 images See the full gallery: Justin Timberlake At The Summertime Ball 2013 - Pictures