I've always believed that I understand what temptation looks like. I imagined it to have a bad-boy smile, sharp cheekbones and most likely a motorbike. Girls of my generation fell for that kind of thing.

I was surprised to discover temptation while drinking coffee at a polished kitchen counter, wearing a pressed collared shirt, and just so happened to be my best friend's father. The invitation had been sufficiently informal.

As we stretched out on the floor of her dorm room during finals week, Melanie had twirled her black locks around her finger and murmured, "Come live with me for the summer." "Your small flat will drive you crazy. Dad...