The unexpected feud between comedian Bill Burr and America’s Got Talent judge Howie Mandel is gaining steam, with both men publicly trading barbs. It all started when Burr appeared as a guest on Mandel’s podcast, Howie Mandel Does Stuff . In the middle of Burr’s interview, Mandel surprised him by bringing out Smashing Pumpkins frontman Billy Corgan . Back in November, Corgan told Mandel on the same podcast that, years ago, his mother confided in him that Burr mi...