A few years ago, I had a very exciting quickie with my girlfriend at a spa. A few months later, I had a naughty email exchange with a girl, spicing up our boring office days. I told her about the great sex at the spa - she answered with a fantasy that built on my experience and introduced her into the real event. We wrote back and forth in the course of a few days, and I decided (with her permission) to share our co-creat...