Joe Jonas wants to do it. Demi Lovato is down too ... “I’ll tell you what James Corden told me before we did Carpool Karaoke. He was just like, ‘Imagine you’re singing to Madison Square ...

Calling all Demi Lovato superfans: you can live it up like a rock star backstage ... for her Las Vegas residency. In contrast, Jonas’ older brother Joe Jonas, offers packages for his tour ...