It's a babysitter's worst nightmare!
YouTube's famous 9-year-old rapper/singer MattyBRaps goes rogue and "Gangnam Style" among the New York City streets. Not even the six smooth-singing Cimorelli sisters could've prepared for this musical mayhem.
And oh, hey, Perez Hilton -- where did you come from?
For more of those Cimorelli harmonies, check out the band's live a capella performance of fun.'s "Some Nights" in the What's Trending studio!