Besonders englisch oder?... Eigentlich sind Australier die best and fairest! immerhin...

weiss nicht wie es auf amerikanisch heissen soll.

  related discussion:f/feine.html
Vielleicht steht da was vernünftiges bei?

Might just be BE !

Pons-Collins:
fein - ...
das ist nicht die feine englische Art - that's not the proper way to go about things

Oxford-Duden:
Art - ...
die feine englische Art - (ugs.) the proper way to behave

Oddly enough, 'not cricket' in this sense would IMO be fine in AE, and I would support it. Go figure. (-:

'Not sporting,' in contrast, is to my ears much more exclusively BE. The AE equivalent is 'not very sportsmanlike,' though I wouldn't recommend it in this context.

'Not very gentlemanly / not very ladylike,' as suggested in one of the older threads, would also be fine, as would 'just not done.'

If you want to know what people would actually say more often, though, it might just be something like, 'That's not right,' 'That's not very nice,' 'That's not how you're supposed to act,' etc.

If someone told me "it's just not cricket" I wouldn't have a clue what they were talking about. Contrary to hm--us, my vote is that it is not ok in AE.

'That's not cricket is a bit superannuated in BE these days. Very few people say it in the U.K., and, I'm sure, even fewer in the U.S.A. Current BE 'everydayisms' for 'Das ist nicht die feine Englische Art':

Situation: Somebody jumps to the head of the queue in front of people who've been waiting for hours:

'Hey, that's not on'/ 'You're over the top/OTT',/'You're (way) out of line'

At the end of each of these, the addition of 'mate' is likely - and although 'mate' usually has the meaning of friend, the opposite is the case here!