Must admit trying to think of an 'arse' of an exchange officer and admit I can't think of one.
We had a couple of KC-135 drivers who came to the VC10K for exchange tours who could be so described...
Back in the civilised days before aircrew were required to puff and pant their way around the gym for the 'Fitness Test' thing, a WIWOL chum was on an AV-8 exchange with the ooh-rah mreenkaw over on the US west coast. One day, some crewcut individual with a neck like a birthday cake asked him whether he wished to accompany the squadron on some PT run, doubtless chanting the same bolleaux as in 'Full Metal Jacket'....
He adopted a studious, hurt-looking expression before explaining "A run? A RUN?? Absolutely not! My dear chap, British officers don't run - it would panic the men!"....