Mike Posner recently joined Justin Bieber's "Believe" tour as an opening act and, of course, the guys have been punking each other right and left. Boys will be boys, right?During the Indianapolis show this week, Bieber ran onstage with a mannequin during Posner's opening set. Surprise! That's a mannequin in the middle (Twitter)Then, it was Posner's turn to get him back. "@justinbieber onstage now…I’m about to get him back….watch out!" he wrote before getting revenge.Naturally, Posner decided...Read Full Story