"Well, it can't have been the sex; I guess she instinctively cottoned on to the fact that I'm an appalling unrepentant narcissist, or emotionally unavailable, or socially stillborn, or some similarly vague-yet-plausible late-stage misgiving which I haven't the energy to challenge. I do hope it wasn't the sex. Wait—did I focus too much on sex? No, that's impossible. God, I miss having sex."