A while ago I saw a post, either here or in another forum, about Russian Roulette. It could be a revolver or short drop where the noose might release your neck after a few seconds, or electric chair with full voltage or just a small voltage that you wouldn't detect for five seconds that it's not lethal, or lethal injection that kills you, or just contains enough phenobarbitol to make you begin to lose consciousness but you don't know it until you realize that the injection isn't going to make you lose consciousness, etc. For me it was Russian Roulette with the guillotine: six chambers, I imagine I'd be just an horny as I am in fantasy and when I'm strapped to the board and slid under the blade I can't stop humping even though I know the moment I explode the blade drops. The idea that I'd never know until I'm finished shooting my load and catching my breath that my head is still attached (or not) makes the entire execution even hotter.