9-Year-Old Noah Cyrus Performing 'Smack That' Is Disturbing on Seven Different Levels Maureen O'Connor · 12/16/09 03:19AM Last time we saw Miley Cyrus' little sister, the tyke was posing with stripper poles and wearing patent-leather thigh-high boots. And now: Noah performs an exuberant ass-slapping version of Akon's "Smack That," while Miley and friends cheer her on.