But both are now midstride into a second act that, like the first, they're experiencing together -- but this time on their own terms.
[Laughs] We’ve seen each other go through tough times, good times, in and out of relationships. It feels like we were children, although I guess we were.
Since then, the singers have gone through a roller coaster (rehab and a breakup with Nick's brother for Demi, and a split from his brothers for Nick), but through it all, the pair have only become closer, growing together both musically and personally, calling each other best friends, becoming business partners for a record label, and going on tour together.
To celebrate Demi and Nick's stronger-than-ever friendship, we're looking back at their cutest pictures together.
RED FLAG One thing is to claim that you are best friends. It is possible to have a guy best friend or a girl best friend if you are a guy, but to have matching couple Halloween costumes? Click through the gallery to see other moments where Nick and Demi seemed to be more than just friends.
Joe Jonas is opening up about his brother Nick Jonas‘ close relationship with Demi Lovato in this new interview!