Kelsea Ballerini and Nick Jonas joined forces for an unlikely collaboration at Sunday’s ACMs (April 3) — after Ballerini performed her breakout hit “Love Me Like You Mean It,” she broke into new single “Peter Pan.” Midway through, she was joined by Jonas on guitar (!), who, after he finished shredding, eventually chimed in with background vocals for the last chorus. The pair had great onstage chemistry — Nick even tweeted about how much he was enjoying working with country up-and-comer