Meghan Trainor Performs LIVE with The Backstreet Boys & She's Freaking Out

Backstreet Boys added a sixth member to their group on ABC’s Greatest Hits — Meghan Trainor!

The 22-year-old singer hit the stage with the boy band — Nick Carter, A.J. McLean, Howie Dorough, Kevin Richardson, and Brian Littrell — to perform their chart topping hit “I Want It That Way” on the show.

And let's be honest... Meghan Trainor is all of us while singing with the Backstreet Boys... totally freaking out!

Check out their great performance.