A muggle-born’s sibling sends them a howler in the middle of the school year and it arrives while they eat. When they open it, all it does is simply scream “WHAT TEAM?”. Nearly all the muggle-borns shout “WILDCATS!” before returning to their meal, leaving the pure-bloods in total confusion of what the hell they just witnessed.
Can you imagine Harry trying to parent his children and tell them they need to settle down but then James Sirius just pulls out his edition of Harry James Potter: A History and goes, “When you were my age you followed an alleged mass murderer into a tunnel, faced a werewolf and nearly got killed by dementors. I think I can go to The Bent-Winged Snitches concert.”