Open, Poly, and Still Betrayed

Can Infidelity Exist Without Monogamy?

One of the most common assumptions about non-monogamy is that it eliminates betrayal. If exclusivity is no longer the organizing principle, then . . . so the logic goes . . . infidelity should no longer apply.

And yet, clients in open marriages and polyamorous relationships report profound experiences of betrayal every day, in my practice.

This paradox exposes something essential: infidelity is not defined by the presence or absence of monogamy. It is defined by the rupture of trust, coherence, and shared reality. When those collapse, the nervous system registers threat regardless of how sexually expansive the relationship may be.

Freedom Does Not Replace Integrity

Open relationships and polyamory are often framed as more evolved or more honest relational forms; and in many cases, they are. They can allow for erotic diversity, reduced pressure on a single partnership, and a more explicit engagement with desire.

But openness does not automatically confer transparency. Nor does philosophical alignment guarantee emotional safety.

In consensual non-monogamy, betrayal often takes subtler forms:

• Agreements quietly stretched or selectively interpreted

• Emotional attachments minimized or concealed

• “I didn’t think it mattered” replacing full disclosure

• Power imbalances in who gets to define the rules

• One partner moving faster than the other can metabolize

The injury here is rarely about sex itself. It is about being excluded from the truth of one’s own relationship.

Differential Polyamory and the Problem of Consent

A particularly fraught terrain emerges when partners are not equally aligned in their desire for non-monogamy. One partner may feel genuinely oriented toward polyamory as a relational philosophy. The other may agree out of fear . . . fear of loss, fear of being replaced, fear of appearing unenlightened or “too needy.”

This creates what might be called differential polyamory: an arrangement that appears consensual on the surface, while masking asymmetrical risk underneath.

Consent, in these contexts, is not a one-time declaration. It is an ongoing, embodied capacity. When one partner’s consent is rooted in self-abandonment, silence, or pressure, openness can quietly become another theater for betrayal.

As Jessica Fern emphasizes in her attachment-based work, non-monogamy does not erase attachment needs. It reorganizes them. Without explicit attention to safety, reassurance, and pacing, attachment injury is not avoided . . . it is amplified.

Transparency Is Not the Same as Truth

Many open and poly relationships pride themselves on transparency. And yet, transparency can be partial, curated, or delayed. Information may be shared strategically rather than relationally. Timing becomes a tool of control.

This is where infidelity quietly re-enters.

When disclosure is managed to avoid discomfort rather than to preserve integrity, truth fractures. What emerges is not freedom, but fragmentation . . . parallel realities held by different partners inside the same relationship.

The question is no longer “Are we allowed to do this?” It becomes: “Are we inhabiting the same relational reality?”

Desire, Aliveness, and the Myth of Immunity

Contemporary discourse often frames non-monogamy as a solution to desire’s volatility. If desire wanes here, it can flourish elsewhere. If longing arises, it need not threaten the primary bond.

And yet, as Esther Perel has repeatedly noted, desire is not simply about access; it is about vitality, risk, and recognition. Non-monogamy does not exempt partners from confronting envy, loss, comparison, or fear of replacement. It simply brings these forces closer to the surface.

The myth that openness makes relationships immune to betrayal often collapses when unspoken hierarchies, unacknowledged favoritism, or emotional exclusivity emerge. When one partner becomes “more real,” “more alive,” or more confided in than another, the wound can be just as deep as in monogamous affairs.

Ethics Are Not the Absence of Rules

What differentiates ethical non-monogamy from covert betrayal is not permissiveness, but accountability. Not rules for their own sake, but agreements that are revisited, renegotiated, and honored in spirit, not just in letter.

As Dan Savage has argued in his pragmatic approach to modern relationships, harm is not eliminated by sexual freedom; it is mitigated by honesty, humility, and repair when missteps occur.

When these are absent, non-monogamy does not dissolve infidelity. It disguises it.

The Through-Line: Coherence

Whether monogamous or polyamorous, the defining question remains the same: Can this relationship hold truth and need without someone disappearing . . . emotionally, relationally, or internally?

Infidelity emerges wherever coherence breaks down; where one partner’s lived experience no longer matches the story being told. And as we will explore next, the motivations that drive people into secrecy are rarely about sex alone. They are about need, fear, and the early lessons we learned about what is survivable to want.

The following questions move the direction of this blog series from definition toward lived experience. They are meant to be considered slowly.

• How do you understand consent in your relationships; not just intellectually, but somatically?

• Where have you said “yes” to arrangements, agreements, or dynamics that your body was unsure about?

• What truths feel easy to share with a partner; and which ones feel risky, delayed, or softened?

• How do power, pacing, or emotional hierarchy show up in your relational agreements?

• If your relationship were described honestly by each partner, would the stories match?

You are not being asked to decide whether a relationship style is right or wrong. Only to notice where coherence is strong . . . and where it may already be fraying.