Structures describe agreements
Adult relationship structures describe how people arrange intimacy, exclusivity, commitment and care. Monogamy, an open relationship, polyamory and other agreements are labels for different possibilities, not a ranking of maturity or worth. Begin with the people involved and the actual expectations. Our monogamy, consensual non-monogamy and polyamory entries define common terms; the agreement still needs ordinary words.
Relate's overview describes open relationships, polyamory and other arrangements while emphasising knowledge and consent of those involved or affected. Its examples are not a rulebook for every group. Some people use an open relationship to mean permission for certain sexual connections; others include emotional relationships. Ask what the people mean before assuming a model from a label.
A person may be single, partnered, living apart, cohabiting or in a long-distance relationship while using any of several intimacy agreements. Household and parenting responsibilities may be separate from sexual exclusivity. Do not assume that legal marital status describes every boundary, or that a non-monogamous label tells you how many partners someone has at this moment. The structure is a living description, not a prediction of behaviour.
Write the parts that matter
A useful agreement may cover what kinds of outside connection are welcome, what information is shared, what stays private, how time is allocated, sexual-health discussions and how a person can ask for change. Relate's trust guidance notes that trust includes disclosure, time and space as well as sexual fidelity. “We are exclusive” may need clarification about online relationships or dates; “we are open” may need clarification about privacy and availability.
Discuss the agreement with every person whose choices it affects. Someone newly joining an existing arrangement should be able to ask what is already promised and what they themselves can decline. A partner who dislikes a proposed structure should not be offered only a choice between agreement and blame. The negotiation entry reminds readers to separate a proposal from an obligation. If a boundary changes, inform affected people before acting as though the change had been accepted.
Keep practical matters visible. If two partners live together, an arrangement about dates elsewhere may affect shared time, guests, money or confidentiality. These do not imply sexual permission, but they can determine whether the plan is workable. Ask what information each person needs for their own decisions and which details belong to another person's privacy. An agreement can be reviewed without requiring everyone to disclose every private thought.
For instance, two people may agree that another relationship can develop but disagree about whether introductions are expected. Ask who wants to meet whom, what information would be helpful, and whether a meeting can be declined. Do not volunteer another person's name or private history as proof of transparency. A clear agreement protects the agency of people who are not in the room when the first conversation takes place.
Distinguish consent from pressure
A consensually non-monogamous relationship requires actual agreement, not one person's declaration that the relationship has changed. Relate says rules should be worked out without coercion and revisited as circumstances change. Conversely, monogamy is not automatically controlling; people may freely choose exclusivity. The test is whether those involved can ask, refuse and leave a proposed arrangement without threats or punishment. Our relationship consent guide addresses that ongoing choice.
A desire mismatch does not by itself make another structure the solution. Relate's pressure guidance describes how fear of a partner's reaction can make a difference in preference coercive. If a person agrees to an open arrangement only to avoid losing housing, care or affection under threat, the pressure needs attention first. Our desire differences guide looks at the original concern without prescribing a structure.
Do not confuse a breach of an agreement with a disagreement about whether the agreement should exist. Name what was actually agreed, what happened and what each person needs now. Relate's trust page discusses change and repair, but nobody is owed immediate forgiveness or a continuation of the same structure. If coercion or abuse is present, private support may be safer than a joint renegotiation.
Include access and relationship diversity
An arrangement should be possible for the people involved to understand and use. Scope's intimacy guidance encourages discussing physical, emotional and sexual expectations and the privacy needs of disabled people. Do not infer someone's preferred structure from disability, gender, orientation or a need for care. Ask about their own choices and whether communication or access support is needed to make decisions privately.
The relationship anarchy entry describes one approach that questions conventional rankings between relationship types. A person using that label may still have commitments and boundaries; ask rather than assume that “no hierarchy” means no care obligations. Another group may deliberately prioritise one partnership. Neither phrase should erase the voice of someone whose time or intimacy is affected.
Pink Therapy's UK directory includes therapists familiar with diverse relationship structures, while COSRT's therapy information covers relationship and intimacy concerns. These are support routes when people want help clarifying agreements or conflict, not endorsements of one model. Ask a practitioner about relevant experience and current fees before booking.
Compare adult relationship structures
This table summarises common usage; the agreement between actual people always needs more detail. Essex Sexual Health Service outlines monogamy, monogamish arrangements, open relationships, swinging, polyamory and relationship anarchy. Relate also describes varied non-monogamous arrangements. Neither a label nor this table establishes what a particular adult has consented to.
| Structure | Emotional involvement | Sexual involvement | Typical agreements | Where to read more |
|---|---|---|---|---|
| Monogamy | Usually one romantic partnership; friendships and other caring bonds still matter. | Sexual exclusivity between partners, if sex is part of their relationship. | Define exclusivity, online contact, privacy and what counts as a change. | Monogamy meaning |
| Monogamish | Usually a central partnership, with the emotional limits discussed explicitly. | Mostly exclusive, with occasional outside experiences agreed in advance. | Specify exceptions; “occasional” does not give automatic permission for any person or event. | Opening up a relationship |
| Open relationship | The main partnership may remain romantically exclusive; usage varies. | Outside sexual connections may be agreed, with separate consent from everyone involved. | Discuss information sharing, safer sex, time, overnight stays and changing feelings. | Consensual non-monogamy |
| Swinging | Often centred on an established partnership; friendship or feelings cannot simply be assumed away. | Agreed social or shared encounters with other consenting adults; participation can always be declined. | Agree individual limits, privacy, invitations and how either partner can stop. | Swinging in the UK |
| Polyamory | Multiple loving relationships are possible with everyone’s knowledge and agreement. | May include sexual relationships, but sex is not required in every connection. | Discuss commitments and power: hierarchical, non-hierarchical and solo approaches; kitchen-table or parallel contact. | Polyamory and its types |
| Relationship anarchy | People question automatic rankings between romantic, sexual and other relationships. | Individually agreed; the label does not require multiple sexual partners or sex at all. | Make each commitment explicit rather than assuming a standard relationship package. | Relationship anarchy |
| Celibate or asexual partnerships | Can include deep affection, romance, shared care or other chosen bonds. | Celibacy means choosing not to have sex; asexuality concerns attraction and does not dictate behaviour. | Discuss welcome affection, sexual boundaries, exclusivity and expectations without trying to change an orientation. | Asexuality and demisexuality |
In the agreements column, the examples are conversation prompts rather than a claim that everyone follows those rules. A person may have several important emotional bonds while choosing sexual exclusivity. Another may agree outside sexual contact without wanting another romantic partnership. Ask about those dimensions separately, and avoid promising that feelings can never change. What matters is how people communicate changes and respect each other’s choices.
Stonewall distinguishes asexuality from celibacy and sexual attraction from romantic attraction. An asexual person may have a romantic relationship, choose sexual activity or decline it; no single arrangement follows from the identity. Celibacy describes a choice about sexual activity, which people may make for different reasons. Neither label makes a partnership less meaningful or permits intrusive questions about someone’s private life.
Polyamory also has several dimensions. Hierarchical and non-hierarchical describe how priority or authority is understood; solo polyamory emphasises personal autonomy. Kitchen-table and parallel describe preferences for contact between partners’ partners. These descriptions can overlap rather than forming exclusive boxes. The expanded polyamory guide explains the vocabulary, while the polycule entry describes a connected relationship network.
Use the comparison to identify a question worth discussing, not to select a relationship model for someone else. Ask what each person wants to keep, what they want to change and what they could decline without punishment. Consider existing commitments to people outside the conversation. If a proposed structure relies on secrecy, coercion or another adult having no meaningful say, choosing a different label does not resolve that problem.
Common questions about structures
Is monogamy the default everyone must choose? No. Adults can choose an arrangement they understand and want.
Does open mean no boundaries? No. Clarify the particular permissions, privacy and responsibilities.
Is polyamory only about sex? No. Some people use it to include multiple loving relationships.
Can an agreement change? Yes, through a new conversation involving affected people, before anyone acts on a new assumption.
Is non-monogamy a fix for unequal desire? It is not a remedy to impose; everyone affected must freely choose it.
When to get help with an agreement
If people feel safe but keep misunderstanding the arrangement, Relate offers relationship support and COSRT lists specialist therapists; Pink Therapy can help find a practitioner familiar with relationship diversity. Check qualifications, access, confidentiality and current fees on the provider's own site. A useful first question is “Which promise do we each believe we made?” rather than “Which label is right?”
If a partner threatens to disclose an identity, imposes a structure or punishes refusal, seek private abuse support rather than mediation. Galop supports LGBT+ people experiencing abuse. The UK help directory points to other services. Immediate danger calls for emergency help. This guide maps agreements and support; it does not decide a fact-specific legal question.