Aah safewords
We don't have one a) because our play is usually quite light b) cos she knows me well enough to push but not too far and c) if it comes to it I just say "can we stop please I have cramp or my nose is itching....."
However, and I have told this story before so sorry regular readers! Many moons ago while doing a strapping session with Mistress Morgan I was given the safephrase Oranges are not the only fruit. Being the tough guy I am I lasted for hours and hours but finally I had to safeword
Unfortunately when I uttered it I forget the not and said "Oranges are the only fruit" It took a few more whacks before I realised my omission