"Speechless" is right! Dan + Shay shocked fans at their pre-Super Bowl gig in Miami this past Saturday when they brought up Demi Lovato to join them for a powerhouse performance of their hit single. Billboard reports that Lovato surprised fans when she got up from her seat in the VIP section belting out the song's opening lines. Their mutual manager Scooter Braun revealed Sunday on Instagram that Lovato had come backstage before the show to say hi to Dan Smyers and Shay Mooney, resulting in a singalong that led to her onstage cameo. "@ddlovato came to see @danandshay last night and they started talking music and this happened backstage which led to an amazing surprise on stage. Wow," he wrote alongside video of their impromptu moment. The next day, Lovato went on to deliver a moving performance of "The StarSpangled Banner" before kickoff.