Marital fidelity is typically assumed to be agreed upon once you take your marriage vows at the wedding and is sanctified by most religions. However, statistics tell us that you cannot rely either on personal assumptions or systematic codes to ensure faithfulness in your marriage. Therefore, a new approach to fidelity is needed — a.k.a., the “new monogamy.” 
The new monogamy is based on the idea that fidelity in marriage is a choice that you and your spouse/partner make together. It means that monogamy is negotiated collaboratively at the beginning and throughout your marital relationship.
Before I get into negotiating fidelity in your marriage, let’s look at what the “old monogamy” was based on.
The Psychology of the "Old Monogamy"
Esther Perel, who wrote about maintaining a satisfying sexual relationship over the long haul of marriage, has some insights about our profound belief in the “old monogamy.”  She suggests that monogamy has its psychological roots in our early experience—with our primary caretaker(s) in which love is unconditionally given wholeheartedly without our having to make any effort at all. How delicious! This early experience is of a “oneness” with the other—there is no distinction for the baby between him/herself and mother—the ultimate togetherness.
Of course, what is true is that the mother knows and cares about many other people, particularly the father—her husband. Perel notes that the mother was never totally faithful, not even once upon a time!
Perel’s term for the old monogamy is “monolithic monogamy,” which is the ultimate seeking of exclusiveness with another person. This is the idea that there is one person out there who can be everything you want: confidante, best friend, and passionate lover—your soulmate. Whatever we call it, the traditional view of monogamy became a marker for our own “specialness.” It is this specialness that deserves exclusiveness.
It is because we have claimed monogamy as a marker for our own “specialness” that when infidelity occurs it feels like we have been personally betrayed—what has been betrayed is our sense of “specialness”—truly unforgivable.
Fidelity as Conviction, Not Convention
The best approach you can take in your marriage is to adopt Perel’s position that fidelity is a matter of conviction rather than convention. As noted, this means that you are willing to accept that monogamy is no longer a societal given and, with self-reflection, need not be driven by subconscious wishes for “specialness.” It is best seen as a choice you and your partner are making and remaking together over the course of your marriage.
Negotiating a New Monogamy in Your Marriage
Negotiating a “new monogamy” is enhanced by the understanding that the convention of “old monogamy” is based on early longing for “specialness,” which we try to re-create in our marriage. Better to negotiate and re-negotiate fidelity as a measure of the commitment to your relationship, rather than trying to fulfill our wish for “specialness.”
In contrast to seeking “specialness” in your relationship, understanding that you and your spouse are unique people who are committed to an equitable and sustainable marriage through the process of negotiation. The “specialness” is in the relationship not in you as an individual.
What You Need to Negotiate
Here are three important things to consider when you negotiate “new monogamy:” honesty or openness, outside relationship, and sexual fidelity. 
- Being honest and open refers to what you agree to tell each other about your relationships with other people. This can include mentioning that you are attracted to and may have fantasies about another person.
- Outside relationships refer to deciding on the limits on the nature of your relationship with other people. Is it okay to share personal information, intimate thoughts, meeting colleagues for dinner, etc?
- Sexual fidelity also needs to be defined. What does sexual fidelity mean to the two of you? What about “lusting” after someone, pornography use, emotional and/or sexual relationships that happen on the Internet?
A Note About Sexual Fidelity
Each of you must take the time to reflect on your own thoughts and feelings about sexual fidelity in your marriage. Examine your implicit view of sexual monogamy. This is likely to be influenced by your own family background, religious beliefs, traditional sex roles, personal moral values, and personal insecurities. Each of you are likely to have a different understanding of the implicit agreement to the “old monogamy.” Such implicit ideas may include: 
- “We promise to be faithful until one of us grows tired of the other.”
- “I know you won’t cheat, but I probably will.”
- “I’ll be faithful, but you won’t because you’re a guy.”
- We’ll be faithful except for a little swinging when we go on vacation.”
You must make these implicit ideas explicit. These implicit views are what you need to talk about with your spouse as you negotiate your new monogamy.
A Final Thought
Fidelity must be a conscious choice you make—one that can encourage the emotional creativity to be able to get along for that many years. This requires the relational competencies including, self-awareness, conscious empathy, and kindness. Fidelity is a choice that you must negotiate regularly to protect your most intimate bond while you both continue to grow as individuals.
- It’s time to challenge the “old monogamy” and embrace “new monogamy.”
- Fidelity in your marriage is not a marker of your “specialness.”
- Specialness is in the relationship not in either of you as individuals.
- Fidelity in marriage is a matter of conviction, not convention.
- Make fidelity a choice the two of you can negotiate.
- The "new monogamy" is about negotiating honesty or openness, outside relationships, and sexual fidelity.
1. Nelson, Tammy. The New Monogamy: Redefining Your Relationship After Infidelity. Oakland, Ca.: New Harbinger Publications, 2013.
2. Perel, Esther. Mating in Captivity: Unlocking Erotic Intelligence. New York: Harper Paperbacks, 2007.
3. Nelson, Tammy. The New Monogamy.
4. Nelson, Tammy. The New Monogamy.