Okay, so I should have copied your entire post. Here it is:
I mean to demean when I call a Brit a Brit, but not when I call a Japanese a Jap.
The Brits can be a bit snooty but I feel a real kinship with the shy politeness of the Nipponese people
except for that time they bombed Pearl Harbor.
- my emboldening
Let’s substitute “n word”, “Paki”, “Mick”, “Red Indian” or any other word or phrase you wish to use to demean a group, for “Brit” or “Brit"s - does that make it any clearer? If it’s a joke it should have been made very clear that it was an attempt at humour and that distinction wasn’t made.
And what SL said.