"Piece of piss" "Piss off" "Taking the piss" "Pissed" As another Englishman, I think a teacher wouldn't feel comfortable using any of these in front of other peoples' primary school children — that aside I think these are all fairly common usage with no implied anger / offense. It might be a class thing though. Having said this, you get all sorts on the web. If you're feeling sensitive, how about… P(HP)i(zed)St(ylesheets)? I think common convention for people who really dislike slang words with scatological etymology is that the words are rendered inoffensive if badly spelled (hence asterisk-ization, etc). Better off-piste than pissed off, methinks.