Gilbert Carrasquillo/GC Images; Theo Wargo/NBC via Getty When Billy Corgan appeared as a surprise ... “A really good friend of mine said to me, looking around, ‘Okay, now tell me the truth.’ ...

Billy Corgan still ... of mine said to me, looking around, ‘Okay, now tell me the truth.’ And I said, ‘I don’t think so. I don’t think we’re related,'” Corgan told the outlet.

Billy Corgan‘s friends are “convinced” he’s Bill Burr‘s half-brother, and have encouraged him to get a DNA test. READ MORE: Billy Corgan on his new podcast ‘The Magnificent Others ...