Beth’s affair shook her marriage to the core. Her husband was devastated, and she was panicked. She still loved him deeply and didn’t want to lose the life they’d built together by ending their marriage. But limiting her romantic life to a monogamous relationship with her husband, Beth realized, was impossible. An open relationship, or ethical non-monogamy in this case, seemed to be a far better choice — one that might save her marriage.

Before she met her husband, Beth was a free spirit floating through no-strings-attached hookups with a circle of male friends. In the early years of her marriage, she accepted that her days of untethered intimacy were over. The memories of non-monogamy tugged at her sometimes, but her love for her husband and children always pulled more strongly. Sacrificing that youthful pleasure was worth what she’d gained in her new life. Besides, she’d made a commitment to stay faithful to her husband. And that was that.

Or so she thought.

Beth and her husband worked past her affair, and then, in a series of long conversations that took place over the course of years, negotiated a new agreement: They’d embrace ethical non-monogamy and open their marriage to other romantic partners while still holding tight to each other. Beth stoked some old flames and lit some new ones. Despite his initial reluctance, her husband embraced the new phase of their now polyamorous marriage and entered into a long-term relationship with a woman he’d met on an online dating site.

As Beth and her husband’s sex lives grew to involve more people, a funny thing happened to the two of them: Free of any fear or worry about potential cheating, they treated each other with newfound trust and openness. Beth even helped her metamour, the term for her husband’s girlfriend, get a job at her company. Beyond having to explain to co-workers why her husband kissed two women when he visited the workplace, the stress drained out of their relationship.

“It saved our marriage,” Beth said. “But that’s probably only because there was something to save.”

An open marriage isn’t for everybody, but as Beth’s story shows, it can work very well for certain people open to ethical non-monogamy. A growing number of Americans are reconsidering whether monogamy is a necessary part of a relationship, and consensual non-monogamy (CNM), has become more accepted and widespread. Although certain therapists and relationship experts have been slow to adapt to the change, a group of cutting-edge researchers, advocates, and writers believe CNM is a great option that should be considered more often. Many even believe it could define the future of American marriage.

Americans today are clearly curious about alternatives to monogamy. Mainstream news outlets, books, and films have put polyamory and other forms of CNM in the spotlight. Meanwhile, internet searches about polyamory and other forms of open relationships have spiked over the past 10 years. And this curiosity isn’t just in the media and online. A recent Kinsey Institute research poll estimated that 20 to 25 percent of Americans have engaged in some form of CNM at some point in their lives, a figure roughly equal to the percentage of Americans who own cats as pets. And that number is likely to increase, as evidence shows that people under 30 are more open to CNM than older age groups.

While couples are reconsidering monogamy, most of the relationship experts they turn to for advice remain faithful to the principle of monogamy, particularly within the context of marriage. As demonstrated by a 2014 international multi-faith Vatican conference on marriage, religious authorities aren’t very flexible about monogamy and marriage (with some notable exceptions).

One might expect the secular, forward-thinking, and emotionally evolved world of relationship therapy to hold more progressive views of CNM, but that is by and large not the case. Elisabeth Sheff, the author of the book The Polyamorists Next Door, is one of America’s foremost experts on polyamory. She says that psychological textbooks and courses teach that all deviations from monogamy are equal. Therapists are instructed to treat CNM as infidelity regardless of consent. All instances of non-monogamy are treated as violations of trust, evidence of power imbalances, and trauma that requires effort-intensive healing.

“Either they do not address non-monogamy at all, or they only address it as cheating,” Sheff said. “There’s zero discussion about how it might be consensual.”

With therapists, by and large, viewing CNM as corrosive for relationships, couples who think it is, or might be, okay for them, are deprived of the help they need. There are signs, however, that this situation may be changing.

In 2017, influential social psychologist Eli Finkel urged members of book clubs across America to question their preconceptions about consensual non monogamy. Finkel is the director of Northwestern University’s Relationships and Motivation Lab, and a regular contributor to publications like The New York Times and Scientific American. In his best-selling book The All or Nothing Marriage, Finkel explored the historical evolution of marriage and found that today’s most successful marriages are far more fulfilling than those that came before.

Problems arise, however, because not every marriage is performing at its peak. While the strongest marriages require time and effort beyond most married couples’ reach, many couples expect ideal results nonetheless and are disappointed when their expectations aren’t met.

For couples in marriages that aren’t meeting their high expectations, Finkel suggests considering several “recalibrations” to their marriage, ranging from spouses living separately to the “high risk” option of CNM.

“All marriages have certain strengths and certain limitations, certain ways that are highly satisfying for the partners involved, certain ways that are less satisfying,” Finkel said. “And there are many, many ways that we can address places where one or both partners feels that his or her needs aren’t being fully met. One of which is relevant when people feel like their sexual needs aren’t being fully met.”

Finkel recognizes that sex is a complicated aspect of a relationship, and stressed that opening up a marriage doesn’t work for most people. Indeed, just broaching the topic of CNM could court disaster. “Sex and love are frequently linked and sometimes, they’re linked in ways that we don’t anticipate,” Finkel said.

Finkel isn’t alone in his thinking. A growing number of therapists and educators are recognizing the need to provide care for couples in open and nontraditional relationships. For the past several years, Sheff has spoken to relationship therapists across America about polyamorous marriage, ethical non-monogamy, and other forms of CNM. Through her partnership with the American Association of Sexuality Educators, Counselors and Therapists, she’s spoken to about 300 relationship professionals about couples who are considering or have started engaging with non-monogamy.

Sheff said that therapists dealing with CNM first need to distinguish between cheating and consensual and ethical non-monogamy. Once they’re over that initial hurdle, therapists need to strive to put their clients’ open marriage in the right context.

“If your clients come to you and say that they’re polyamorous, but really fighting a lot about money, you can’t say, ‘Wait, let’s get back to this sex thing,’” Sheff said. “The money has nothing to do with polyamory, but if the therapist can’t move on past that and their own obsession with it, then it’s ineffective for the clients. They’re not being well-served.”

Sheff’s career illustrates the institutional bias facing CNM. After earning her Ph.D. in Sociology, she published numerous studies on polyamory. Getting published in academic journals is usually a path to a tenured professorship, but Sheff feels that her interest in polyamory sunk her prospects in academia. “This topic cost me my career,” she says.

With social scientists reluctant to study CNM, several psychologists are mining the subject for their research. Sheff joked that she had to dial back her claim on being America’s foremost academic expert on polyamory after reading University of Michigan psychologist Terri Conley’s research comparing monogamous and non-monogamous partners.

Sheff also singled out the work of Amy Moors and Heath Schechinger, a research team working to change how psychologists understand and approach CNM. Moors, a psychology professor at Chapman University and a Kinsey Institute Fellow, and Schechinger, a behavioral health psychologist at UC Berkeley, have reached out extensively to CNM practitioners. Their work has led to a greater understanding of the CNM population — Moors co-wrote the study about the percentage of Americans who’ve engaged in CNM cited earlier in this story — and recommendations about how therapists and counselors should care for CNM couples.

“We see relationship-structure diversity as the next wave of where we hope [psychology] goes in terms of raising our collective consciousness about the way this population is being stigmatized,” Schechinger said.

For their recent study “Harmful and Helpful Therapy Practices With Consensually Non-monogamous Clients,” published in the Journal of Clinical and Consulting Psychology, Moors and Schechinger asked hundreds of CNM couples about their experiences with therapy.

“There was no real data that addressed therapy, especially not on a larger scale,” Schechinger. “A lot of it focused more on qualitative, so really small samples. So we wanted to do something that both captured something at a larger scale.”

Currently, Moors and Schechinger are looking for volunteers to join the Task Force for Consensual Non-Monogamy they’re organizing for the American Psychological Association’s Division 44, which specializes in the psychology of sexual orientation and gender. With it, they hope to create new research and resources and advocate to include CNM relationships in psychological research and education. They’ve also persuaded the American Psychological Association to include a searchable term of consensual non-monogamy in the APA’s therapist locator system in hopes of connecting CNM couples with therapists attuned to their needs.

“So if you want to find a therapist who specialized, or at least had working knowledge [of CNM], you can go into that space without worrying about being belittled having to do a lot of explaining to a therapist,” Moors said. “Instead you can find a therapist with working knowledge. We’re hoping within the next few months this goes live and it can become a searchable term.”

While Schechinger is hopeful about the future of CNM research and advocacy, he acknowledged that the subject still faces challenges from stigma and lack of awareness.

“The field is producing much more research,” Schechinger said. “I would say that there’s a growing awareness of it but that we are still very far off from being where we need to be.”