Heather Morris is best known for playing the lovable ditz Brittany S. Pierce on the Fox hit Glee. She made a name for herself in the ensemble comedy thanks to her killer dance moves (she was after all a backup dancer for Beyoncé). Morris took a break from the dance floor to chat with David Letterman on January 9. During her interview, she discussed moving in with her athlete boyfriend, what to expect from Glee's upcoming Michael Jackson tribute episode and the YouTube video that will never get old. Check out the clip below to find out more, including who’s smarter: Heather or Brittany!