Green Day's Mike Dirnt Joins Billie Joe Armstrong in American Idiot

Fans have been flocking to the St. James Theatre to catch Green Day front man Billie Joe Armstrong rock out as the charismatic drug dealer St. Jimmy in American Idiot, but on January 22 audience members got an extra surprise when Armstrong announced that his bandmate, Green Day bassist Mike Dirnt, was in the house. Dirnt hopped onstage with Armstrong, show stars John Gallagher Jr., Stark Sands and the rest of the Idiot crew to join in for the musical's encore, the band's mega-hit song "Good Riddance (Time of Your Life)." Take a look below!