"I'm going to drop the kids off at the pool" Heard that a few times and didn't know what these people were going on about! The penny dropped after a while...Excuse the pun...
When I used to work in a newsagents shop many moons ago,my boss would just say he "was going to turn his bike round" and then he would disappear in the loo.
My Mum used to ask us ''Have you spent a penny?'' for a #1 or ''Have you done your duty?'' for a #2.
I was a bit perplexed when we saw a Policeman directing traffic and my Mum said ''Look, there's a policeman doing his duty''