Types of Open Relationships: 7 Common Styles Explained

“Open relationship” sounds like one thing, but ask ten couples what theirs looks like and you may get ten different answers. Some are almost monogamous with a little flexibility. Others give each partner a lot of independence. Understanding the main types of open relationships helps you find words for what you want, spot what you don’t, and talk about it with less guesswork. This guide walks through the common styles, how they differ and how to choose one together.

What counts as an open relationship?

An open relationship is usually described as one with a primary emotional and intimate bond between partners who agree to at least the possibility of sexual or emotional intimacy with other people (Wikipedia). The International Society for Sexual Medicine (ISSM) puts it simply: in an open relationship, partners agree they can be sexually involved with other people outside their primary relationship (ISSM, 2024).

The key ingredient is consent. Everyone involved knows the relationship is open and has agreed to it. That’s what separates an open relationship from cheating.

It’s also not rare. In two nationally representative US samples of single adults, 21.5% said they had been in a consensually non-exclusive relationship at some point (PsyPost, reporting Haupert et al.).

If you’re unsure how open relationships compare to polyamory, our guide to polyamorous vs open relationships covers the difference in detail.

The main types of open relationships

These categories overlap, and plenty of relationships mix elements from several. Think of them as starting points for conversation, not boxes you have to fit into.

1. Monogamish

Writer Dan Savage popularised “monogamish” for committed relationships that are “mostly monogamous, but there’s a little allowance for the reality of desire for others” (The Advocate, 2011). In practice, that might mean occasional, clearly limited exceptions, while day-to-day life looks monogamous.

Might suit you if: you value a mostly exclusive partnership but want room for honesty about attraction.

2. Classic open relationship

This is the style many people picture first: a committed couple who stay romantically focused on each other while each being free to have sexual connections elsewhere (ISSM, 2024). Outside connections may be casual, and couples often agree on limits around emotional involvement, time or how much they share.

Might suit you if: you want variety and independence while keeping one central romantic partnership.

3. Swinging

Swinging usually involves a committed couple connecting with other couples or individuals, often together and often in a social setting such as a party or event (ISSM, 2024). The emphasis tends to be on shared experiences rather than separate dating lives.

Might suit you if: you’d rather explore as a team than date independently.

4. Open marriage

An open marriage is simply a marriage with consensual non-monogamy (Wikipedia). It can follow any of the other styles on this list. What makes it distinct is the extra layer of shared life, such as legal ties, finances, a home or children, which often shapes the agreements.

Might suit you if: you’re married and want to keep that commitment while opening up in a way that protects your shared life.

5. Don’t ask, don’t tell (DADT)

In a DADT arrangement, partners agree that outside connections are allowed but choose not to share details. For some people, not knowing feels easier. For others, it can create anxiety or make it harder to notice when an agreement has been broken. Our article on “don’t ask, don’t tell” in ethical non-monogamy looks at the pros, cons and questions to ask before choosing it.

Might suit you if: you both want some privacy and feel secure without the details, and you still agree on what must be shared, such as anything affecting health or safety.

6. One-sided or hybrid open relationships

Sometimes only one partner is non-monogamous while the other stays monogamous. This is often called a hybrid or mono-poly relationship (Wikipedia). It can work well when the monogamous partner truly chooses it, rather than accepting it out of fear of loss. Our guide to navigating a one-sided open relationship covers how to keep it fair for both of you.

Might suit you if: your needs differ, and both of you feel the arrangement is chosen rather than tolerated.

7. Hierarchical and non-hierarchical open relationships

Many open relationships have a clear “primary” partnership that comes first in time, decisions and future plans. That’s a hierarchical setup. Others try not to rank relationships at all, giving each connection room to find its own shape. Neither is automatically better, but it helps to name which one you’re in. Our piece on hierarchical polyamory explores how hierarchy works and how to handle it with care.

Might suit you if: you want to be honest with new partners about where they’ll stand from the start.

Close neighbours: polyamory and relationship anarchy

Two related styles often come up alongside open relationships. Polyamory involves romantic relationships with more than one person at once, with everyone’s knowledge. Relationship anarchy is a philosophy that sets aside traditional relationship rules and rankings (ISSM, 2024). Some open relationships grow into one of these over time.

Why the type matters less than the agreements

Two couples can both call themselves “open” and live very differently. The real shape of a relationship comes from what you agree on. Common topics people negotiate include honesty, relationship maintenance, trust, boundaries and time management (Wikipedia).

Questions worth talking through, whichever type you choose:

• Who: Are friends, exes or people in shared circles okay?
• What: Is this about physical connection, emotional connection or both?
• How much: How will you balance time, energy and attention?
• What you share: Do you want details, a heads-up, or neither?
• Health: How will you handle sexual health, testing and protection?
• Review: When will you check in and adjust?

For more on drafting these, see our guide to open relationship rules.

What research says about different types

Researchers increasingly treat these styles as distinct rather than lumping all non-monogamy together. One 2018 study, for example, compared people in open, swinging and polyamorous relationships separately and found differences between the groups, while monogamous participants were satisfied overall too (Sex and Psychology, on Conley et al., 2018). The same source notes a 2015 review that found the well-being and relationship quality of consensual non-monogamists were “not significantly different from that of monogamists.”

Different types are also seen differently by others. In a study of stigma, people’s ratings of open relationships generally fell between monogamous relationships and swinging, which was viewed most harshly (Balzarini et al., 2018). That’s worth knowing if you’re deciding who to tell.

How to choose the right type together

Step 1: Start with why

Before picking a label, talk about what you each hope to gain. Variety? Independence? Exploring an identity? Shared adventures? Your reasons often point to a type.

Step 2: Name your non-negotiables

Each of you lists two or three things you need to feel safe, and two or three things you’re unsure about. Look for overlap.

Step 3: Pick a starting point, not a forever

Choose the type that feels closest, and agree to treat it as an experiment. Many people start monogamish or with clear limits and adjust from there.

Step 4: Agree on check-ins

Set a regular time to talk about how it’s going. A simple script: “What’s felt good this week? What’s felt hard? Is there anything we want to change?”

Step 5: Remember other people’s needs

Anyone you date has feelings and needs too. Being clear about your type and agreements upfront is one of the kindest things you can do for them.

A guide for couples opening up

If you’re still working out which style fits, Opening Up: A Starter Guide for Couples walks you through how to ask for an open relationship, choose a style that fits and look after each other along the way, with prompts you can use together.

A note: ENM Living shares general information, not professional, medical or legal advice. For questions about sexual health and testing, speak to a sexual-health clinic or doctor. If relationship changes are causing distress, a qualified, non-monogamy-aware counsellor can help.