The broad umbrella for knowingly agreed non-exclusive sexual and/or romantic structures.
Back to the glossaryConsent & relationships
Consensual non-monogamy
An umbrella for relationship structures in which adults knowingly agree that more than one sexual and/or romantic connection may occur.
Consent & relationships
In brief
Multiple possible connections with informed agreement.
Consensual non-monogamy, or CNM, includes varied arrangements such as polyamory, open relationships and swinging. Its defining feature is informed agreement rather than the number of partners alone. It differs from concealed infidelity because relevant partners know the relationship is non-exclusive.
CNM commonly allowing multiple loving or emotionally intimate relationships.
A partnered arrangement permitting defined outside sexual or romantic connections.
A breach of an agreement; it can occur in monogamous and non-monogamous relationships.
Consent is networked, not transferred
Each person consents to their own participation and agreements. One partner cannot consent on behalf of another person, and being in CNM does not mean being available to everyone.
Disclosure agreements should be clear about timing and privacy. Transparency between partners does not authorise sharing another person's intimate details without permission.
Agreements and communication
Topics may include time, safer sex, disclosure, hosting, finances, public visibility and changing feelings. Agreements work best when they are understandable, realistic and open to review.
Rules imposed through fear or unequal leverage may not reflect genuine agreement. Ending or renegotiating remains available.
Evidence and stigma
Reviews generally find similar average psychological wellbeing and relationship quality in CNM and monogamous groups. A recent meta-analysis found no overall satisfaction advantage for either structure.
CNM people may face stigma in families, workplaces and healthcare. These pressures can affect wellbeing independently of relationship functioning.
Health and law
Partner number alone does not determine STI risk. Testing, barriers, vaccination, activities and communication provide more useful information.
UK relationship recognition, parental rights, housing and benefits may privilege couples or marriage. Personal legal questions require specialist advice.
Non-graphic examples
What the umbrella may include
- Partners agree that additional romantic relationships may develop.
- An open couple defines safer-sex and disclosure expectations.
- Someone declines a new connection despite identifying as non-monogamous.
- A privacy agreement limits what metamours are told.
- Partners revisit an arrangement when time commitments change.
Reviewed 30 August 2026
Keep exploring.
This detailed field note uses the best available evidence without treating one community sample as universal. Evidence limits and UK context are stated where relevant.
Prepared by The UK Kink Guide editorial team. Read the evidence and review methodology.
Found an error or important omission? See how to report a correction.
Explore all 268 entries