The internet is feeling nostalgic after the Jonas Brothers and Jesse McCartney recently appeared on Kai Cenat's 'MafiaThon 3' stream. The ex-Disney stars delivered top-tier vocals and throwback performances, and social media users couldn't help but kick back and relive their childhood memories.Related: Go Off! Rakai Shocks Fans With Hidden Talent During Kai Cenat's 'Mafiathon 3′ (VIDEO)The Jonas Brothers Appear On Kai Cenat's 'MafiaThon 3' StreamKai Cenat's 'MafiaThon 3' is only in its first week but has already delivered some unforgettable moments for fans. On Friday, Sept.