16. Infidelity is never black and white. Everyone has an opinion about marital infidelity, and it’s usually binary: the spouse who cheated is the so-called perpetrator, the spouse who was cheated on is the so-called victim. But the reality is that cheating — and what it means for marriage — is far more complex than that. As therapist Tammy Nelson argues, perhaps it’s time to revisit the concept of monogamy itself, which is under more pressure than ever, what with opportunities to cheat just a mouse click away and ever-increasing lifespans that mean, if couples wed in their 30s, they’re vowing to love, honor, and get busy with only each other for over half a century. If we can admit that most of us are stumped about how to handle monogamy, maybe we can begin to have a conversation that is as complex as infidelity itself.