I had to think this one out carefully, because two previous partners have been excited by edgy games where - either by breath control or by artery pressure - I could hold them in a state where their lives were literally in my hands, and where they were close enough to passing out to feel that they might die right there. And it was a big thrill because, if this is about power exchange, then the power of life and death is universally recognised as the ultimate.

But that didn't quite fit, and I realised that it wasn't what this is about because none of us seriously imagined that I would kill them; the thrill was just that I could, that I had that power and wasn't afraid to use it. If the fantasy had been that I was going to kill them, it would have been a whole different game.