Justin Bieber is quite the prankster and now his tour buddy Mike Posner knows all about it!
The two singers engaged in an all-out prank war during their Indianapolis show on the Believe tour earlier this week and definitely got each other good!
First Justin started it off when he popped up during Mike's opening set and came out with a mannequin! We aren't really sure what's up with his mannequin obsession these days...
Mike got Justin back during his performance when he went out on stage dressed just like him!
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