Thread:Vincentberkan/@comment-4946399-20190728115041/@comment-4946399-20190730121200

I personally think this was just a slip-up from the animators. That they recycled the character designs of David's parents for a random family watching the parade. Or they intended for these kids to be David's siblings, but changed their minds later and simply retconned them from the series, making this cameo an early installment weirdness.