What is this expression "For Pete's sake!" all about? Here, I'll use it in a sentence:
Mum: Baisy would you hurry up and hang the washing out for Pete's sake?
I don't understand. Who is Pete? And why would I hang the washing out for his sake? I don't even know him! If I'm going to hang the washing out at all it's gonna be in the name of my Mum, not this mysterious 'Pete' character.