This is kinda fun, having traveled in the UK and worked with a couple guys from Ireland. (And having read "Trainspotting"
) I don't see Colin Farrell as a wanker. In the US he affects the "badboy" persona which so many women love. And many hate.
other cool words capable of faux pas(tell me if I get these right);
a rubber = eraser
suspenders = garter
a vest = undershirt
bird = woman
Bloody Yank = American who just committed a faux pas
fag = cigarette
windscreen
boot
roundabout