Machine Gun Kelly and Yungblud joined forces after separate gigs in different cities ... with an impromptu performance atop a tour bus that had fans losing their damn minds.
So check it out ... MGK had a scheduled performance Wednesday night at the City National Grove in Anaheim while Yungblud was performing at world famous Roxy Theatre in WeHo. But, just after midnight ... MGK rolled up on his tour bus, spotted YB and, in endearing fashion, yelled, "What's up, you f***? Come here."
Halsey - Man - MGK - Bus - Rooftop
Halsey's man didn't hesitate joining MGK on the bus rooftop and quasi performed their new hit "I Think I'm OKAY" featuring...