Sirius Black’s dad-lore would go crazy. He’s like: “oh I just remembered that time I became an animagus when I was 15 to hang out with your other dad on full moons” and his kid is like “bestie what.” or he says “oh yeah I broke out of Azkaban to kill my ex-best friend who framed me for murder” and the kid just stares at him like “you fucking what now???”