The error was unforgivable, especially for someone who prided herself on being so careful. I told myself it was the carelessness itself that was bothering me, and not my bruised ego. I was, I told myself, above having my feelings hurt when I read what she’d said about me in an email to a different playmate. As far as she knew, her email meant for the “kinky M&A man” had not accidentally gone to me instead. The bulk of the...