My father left my mother abruptly when I was 14 years old, and he hasn’t contacted either of us since. It was a crushing blow for her, and she retreated from the world. She was never bitter about it, but it was devastating. She lost the love of her life for no apparent reason and was left completely alone, except for me. We have both done our best to forget about him. We were extremely close for the next four years and actually slept in the same bed every night. Eventually, we began doing something that most people would consider evil but neither of us has ever regretted. It was just something that happened. And it wasn’t something that just happened once—it went on for two years and ended only when I left to go to university. I haven’t thought about this for years, and it is something my...