All Time Low brought out a few special guests during the Anaheim, California stop of their Sad Summer Fest tour over the weekend.The Baltimore band kicked off the tour in Sacramento on Saturday (August 7), followed by Anaheim on Sunday (August 8) – the latter of which saw them joined by Demi Lovato and Heather Baron-Gracie of Pale Waves.Gracie and All Time Low teamed up for a performance of their recent collaboration, ‘PMA’, while Lovato took it back to last year with a performance of