While some families use Thanksgiving to loaf and then eat and then loaf again, Seth Meyers’s brood has a different tradition: competitive demonstrations of love. On Thursday’s Late Night, Seth had his mom, dad, and brother on for the second annual “How Well Do You Know Your Meyers?†and, as it turns out, the Meyers know the Meyers … pretty well! Hey, if you’re gonna fight at Thanksgiving dinner, you might as well regulate the ritual.