Pete's parents are visiting, and I've heard a few choice Dutch expressions over the past week. One of my favourites is one which they both heard routinely as children:
Als je niet horen wil met je oren
dan moet je het voelen met je billen.
It is very compelling in Dutch, emphatic yet poetic, and the English translation doesn't quite do it justice:
What you don't hear with your ears
you must feel with your bum.
I don't think I could quite gather up the nerve to shout that at my kids at the playground. Not in English, anyway.