From there, the two then "try" to sing A-ha's 1985 hit, "Take On Me," but Handler needs a little help with her vocals from The Voice coach. "You sound like Darth Vader," Shelton says of Handler's singing voice.
While she praised his tunes, she went on to call out his ego. "He's a narcissist," she joked. "[Blake] made me listen to all his albums and then act like I hadn't heard them dozens and dozens of times -- which obviously nobody has."
Check out more of Handler's firsthand account of working with Gwen Stefani's boyfriend: