Watch Miley Cyrus grind on stage and spank Madonna’s butt during a “Don’t Tell Me” and “We Can’t Stop” medley on MTV’s Unplugged concert special on Jan. 29.

A Maine high school principal has banned dances, blaming "MTV and VH1" for teaching students how to grind and twerk.

Miley Cyrus belted out her hits live, grinded with Madonna and twerked up on a horse on MTV’s “Unplugged” Wednesday. It was just like Eric Clapton’s “Unplugged” a couple decades ago.