Gambler brought up an interesting point earlier re an English couple getting snotty because someone asked them if they were from Australia.
It's a fact that guessing at someones accent is a risky business, especially if you get it wrong. I had a Canadian friend who was always being mistaken for an American, and boy did he ever get pissy about it.
Same with New Zealanders, I don't mix 'em up with Aussie's because I have Kiwi pals and am tuned into to the softer intonations. My wife has a Swiss friend who hates being mistaken for being from Germany or Austria and makes no bones about letting you know it.
I used to laugh at what I considered to be over-sensitivity, until someone suggested that I came from Yorkshire. Boy, did my hackles rise, I have only a vestige of my northern accent left, and it is most definitely Lancashire! Bloody Yorkshire people, just like Scots only without the generosity. (that's heavy sarcasm BTW)
All that being said, I now never ask "Are you ****ish" of anyone anymore. I simply ask where someone is from and await the answer.
It's safer that way!
Englishman.
Bring on the dancing girls!