Miley Cyrus performs with Madonna for MTV Tuesday Jan. 28, 2014. The 21-year-old pop star and the 55-year-old Queen of Pop grinded and grabbed each other as they performed Cyrus' hit "We Can't Stop" and Madonna's 2000 track "Don't Tell Me"  Tuesday during a taping in Hollywood. The "MTV Unplugged" special that closes with the duet is set to air Wednesday. (AP Photo/Sandy M. Cohen)

Miley Cyrus performs with Madonna for MTV Tuesday Jan. 28, 2014. The 21-year-old pop star and the 55-year-old Queen of Pop grinded and grabbed each other as they performed Cyrus' hit "We Can't Stop" and Madonna's 2000 track "Don't Tell Me" Tuesday during a taping in Hollywood. The "MTV Unplugged" special that closes with the duet is set to air Wednesday. (AP Photo/Sandy M. Cohen)