Demi Lovato was cool for our iHeartRadio Music Festival in Las Vegas this weekend. She had all of her #Lovatics at the MGM Grand Garden Arena, and around the world tuning in, going wild for her confident high notes. But you know who else was going wild? Demi's boyfriend Wilmer Valderrama, friend and business partner Nick Jonas, and her Camp Rock co-star Joe Jonas.

While Demi was performing her hit "Really Don't Care" on stage, Wilmer, Joe, and Nick were in the audience watching, dancing and singing along, basically having the time of their lives. And thankfully, they snapped a video of their singing, and it's amazing.

Watch Wilmer, Nick, and Joe sing along to Demi Lovato performing at our iHeartRadio Music Festival above!