How Well Do Friends (and Tourmates) Demi Lovato & Nick Jonas Know Each Other? Find Out

What's the most obscure thing on Demi Lovato's tour rider? How about the word Nick Jonas overuses? Billboard put the pop stars and co-headlining tourmates' knowledge of each other to the test during a break from their recent cover shoot

?Billboard Cover: A Candid Conversation With Best Friends Demi Lovato & Nick Jonas on Surviving Disney, Their Huge New Tour and Pop Stardom on Their Own Terms 

So, how did they do? Let's just say Demi has to clarify, "We're best friends, I promise." Check out the exclusive video above and find out Demi's go-to karaoke song, Nick's favorite singer and watch the two rap Eminem for a hot second. Then read this week's Billboard cover story, where the longtime pals talk overcoming their own personal obstacles, politics and whether they'd ever want to be college dorm mates.