Two decades after their split, the singer invited her ex-boyfriend Joel Madden and Good Charlotte onstage during her sold-out MSG concert. She then introduced Joel, Benji Madden, and the band “Good Charlotte” as her long-time friends, to the absolute delight of the crowd. However, the Disney alum is not the only one with a good relationship with Good Charlotte. She later joined Duff, Koma, Joel and Benji backstage for a group “family” photo. (Photo by Amy Sussman/Getty Images)This surprise Good Charlotte performance happened during a historic moment in Duff’s career.