I can't help with the question, but as for bloopers, I just now made a beaut
I've made friends with another mother in my complex, because we put our kids on the school bus every morning. She is of Asian descent, and I assumed (I know) that she was Korean. Today we got to talking about immigration, and it came to light that not only was she not Korean, she is Japanese (ouch). It was cool though, because she didn't immigrate from Japan but from Brazil, so we were off and talking about Brazil. I decided to let it go by and hope she wasn't offended. We made a tentative playdate for the kids, so I don't think so.
But...ouchie. I broke my own rule about not trying to guess someone's nationality, especially if they are Asian. So much history between the countries, and none pleasant.
At least I didn't say "Your daughter must take after her dad, not you"
. The little girl is her stepdaughter.