How Trust Breaks in Non-Monogamous Relationships

Co-authored with Inna Yulman, ALM, MBA,

Source: Image by author

Open or polyamorous relationships can offer profound, diverse, and meaningful connections. Yet, they come with their own unique challenges and require a strong foundation of trust, transparency, communication, and ethical behavior.

In a polyamorous context, cheating does not always fit into traditional definitions. It is not necessarily about secret sexual encounters or emotional betrayals in the way monogamy defines them. Instead, it can involve omitting critical information, controlling the narrative, or misrepresenting the nature of a relationship.

Polyamorous infidelity often stems from a breakdown in transparency. When a partner hides or downplays the reality of their connections or intentions, it makes it impossible for the other to give informed consent. When one person selectively chooses what their partner should know or withholds information that impacts shared agreements, it undermines the ethical framework that polyamory relies on.

Recognizing cheating in the context of open relationships

Cheating, at its core, is about dishonesty, or broken agreements. In an open relationship, compared to monogamous ones, the lines can be more nuanced, but the underlined foundation is about ethical behavior within the agreement and understanding of the relationship. Cheating occurs when someone violates shared rules, withholds agreed-upon information, or manipulates and downplays the truth. The essence of being “open” is not a free-for-all. It is about having clear, consensual guidelines on how, when, and with whom people can explore connections.

Here are some common ways infidelity can manifest in a polyamorous dynamic:

• Breaking a transparency rule
  If partners have agreed to disclose new romantic or sexual connections but one person hides a relationship or admits to it only long after the fact, this dishonesty breaks trust. If a mistake was made, communicating about it as soon as possible would help minimize a rift in the relationship.
• Ignoring sexual health agreements
  If partners have an understanding about safe sex practices with outside connections and one person disregards these agreements without informing their partners, it not only breaks trust but also endangers physical health.
• Exceeding time and availability limits
  Partners may agree on certain limits—like only having outside connections on specific days or not missing important couple times. If someone goes on a date instead of attending a planned anniversary dinner without discussing it, that could be viewed as breaking trust.
• Hiding or misrepresenting intentions
  Suppose you tell your partner you’re only meeting new people in a group or “just friends” context but in reality you’re going on one-on-one dates you never mention. Secrecy and deception themselves become betrayals.
• Refusing to honor veto power
  Some open relationships have a veto agreement whereby each partner can reject a potential outside partner if it makes them uncomfortable. If your partner asks you not to pursue a specific person (such as a mutual friend) but you do so anyway, that can be a form of cheating.
• Gaslighting or minimizing agreement violations
  If a partner crosses an established agreement or they know that an action is well outside of the spirit of an agreement —like spending a “forbidden” overnight with someone—but then downplays it or insists their partner is overreacting (trivializing the partner’s concerns), this compounds the betrayal with dishonesty and emotional manipulation.
• Changing a causal relationship to a deeper one in secret
  You and your partner agree that any external connections will remain strictly casual. After some time, you find yourself developing a deeper bond—regular dates, emotional intimacy, or even calling this person a romantic partner—but you keep this evolution hidden. Covering up the shift in nature violates the original agreement.

Each of these examples highlights the same central principle: The essence of cheating in an open relationship is the intentional violation of mutually established rules, agreements, boundaries, and expectations. What truly matters is clarity, transparency, mutual respect, and honesty about any changes to feelings, desires, or comfort levels. It is an act of respect for each partner to give and receive informed consent.

Building healthy polyamorous relationships

Ethical behavior

Ethical behavior underpins trust in any relationship and is what makes non-monogamous relationships function. It means acting in good faith, respecting boundaries, being upfront, and communicating openly—even if it’s uncomfortable. Everyone has the right to informed choice about new partners, how intimacy is managed, and potential risks. Acting ethically doesn’t mean you eliminate negative feelings or conflicts; rather, it creates a framework in which conflicts can be addressed proactively and respectfully. A break of trust arises when someone withholds information, manipulates facts, or disregards agreed-upon guidelines. It is also important to adhere to the underlying intent of an agreement rather than finding ways around it.

Mutual consent and shared intentions

Consent in an open relationship goes beyond a simple “yes"; it requires ongoing check-ins, clear boundaries, and aligned intentions. Conflicts arise when undisclosed expectations differ, such as one partner seeking casual encounters while the other desires deeper bonds. Cheating occurs when agreed rules are ignored, like forming off-limits emotional ties or violating sexual health protocols. Regular communication ensures trust, honesty, and respect.

Changing expectations

Open relationships evolve as feelings, comfort levels, and life circumstances shift. A purely physical agreement might transform as emotional attachments form. Problems arise when partners resist such natural changes—if one seeks emotional involvement while the other clings to a “no emotions” rule, secret behavior can follow, leading to cheating. Ongoing communication and reevaluation of boundaries allow couples to adapt together, minimizing unintentional betrayals and ensuring that changes happen with mutual consent.

Emotional support

It is important to create space for honest conversations about struggles without judgment. Trust grows when partners feel safe expressing fears and vulnerabilities, knowing they will not be dismissed, rejected, or shamed. Partners should share when they notice jealousy, discomfort, concerns, or insecurity building up. Fostering open dialogue allows partners to navigate emotions together. Supporting and validating each other strengthens a partner’s connection, reinforcing its stability and uniqueness.

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Ongoing communication

Open relationships require ongoing dialogue. Beyond initial rule-setting, couples benefit from regularly revisiting boundaries, sharing emotional responses, and addressing concerns early on. Proactive check-ins maintain connection and prevent misunderstandings. Ethical behavior and mutual consent hinge on this consistent communication.

Conclusion

Open relationships, just like monogamous ones, hinge on trust, transparency, and a commitment to ethical behavior. Mutual consent, clear intentions, and the willingness to adapt to changing expectations are the cornerstones that help couples thrive in such arrangements.

Cheating in an open relationship is not about the presence of multiple partners; rather, it is about the deliberate violation of agreed-upon rules and emotional boundaries. As relationships evolve, so do comfort levels, emotional needs, and daily realities. A willingness to continually communicate and adjust the parameters of the relationship goes a long way in preventing misunderstandings and betrayals.

Inna Yulman, ALM, MBA, is a relationship counselor helping individuals and couples navigate monogamous and non-monogamous dynamics.