Lost in Translation
There are a ton of perks of marrying outside of your culture or country. First and foremost, you get to play all sorts of pranks on your family and your SO while blaming tradition. For instance, the OP’s dad played a hilarious prank on his new wife by telling her that new people in the family have to stand up when they speak.
His family questioned why the wife stood up whenever she spoke, and he blamed it on American culture. It took an entire two decades for the mom to learn the truth. Had she been standing up to speak the entire time or what?