Open relationships and affairs: how they differ

A married person meeting someone else might be having an affair, or might be in an open relationship their partner fully supports. On a profile, the two can look identical. In practice they could hardly be more different, for the people involved and for the partner at home.

Consent is the whole difference

An open relationship is one where both partners know that other relationships are happening and have agreed to them. Usually there are rules, discussed and revised over time.

An affair is a sexual or romantic relationship kept from a partner, who therefore hasn't agreed to it.

That difference shapes everything else. A partner who knows can make informed choices about their own sexual health, can say when something isn't working, and can leave if the arrangement no longer suits them. A partner who doesn't know carries risks they can't see.

The main types of open arrangement

Consensual non-monogamy is the umbrella term for relationships where everyone involved knows there are other partners. Within it, people use a handful of labels:

• Open relationship: a couple who stay each other's main partner and have sexual relationships with others.
• Swinging: couples meeting other couples or individuals for sex, often together, usually with the emotional relationship kept between the couple.
• Polyamory: more than one loving or romantic relationship at once, with everyone's knowledge.
• "Don't ask, don't tell": permission given in principle, with an agreement not to share details.

The labels matter less than the agreement behind them. Two couples who both call themselves open can have completely different rules.

How open arrangements usually work

There is no single model. Common elements include:

• Rules about who and where: no friends or colleagues, no one local, not in the family home.
• Rules about what is shared: some couples want to hear everything, others prefer to know nothing beyond the fact of it.
• Sexual health agreements: protection, regular testing, and telling each other about results.
• Veto or pause: either partner can ask to stop or slow down.
• Regular check-ins: a set time to talk about how it is going.

Arrangements built around "don't ask, don't tell" sit somewhere in between. Consent has been given in principle, but the partner knows very little. They can work, and they can also slide into something that feels very much like an affair to the person at home.

Why some people don't open the relationship

Most people who have affairs never suggest an open relationship. The reasons are understandable: they expect their partner to say no, they fear the conversation itself will end the marriage, they want something exclusive rather than shared, or they feel the relationship at home is too fragile to survive the question.

Those fears are often realistic. They are still worth testing, because the alternative carries its own risks, explained in our guide to questions to ask yourself before an affair.

Raising the subject with a partner

How you raise an open relationship matters as much as what you ask. Lead with feelings, leave room for any answer, and don't expect a decision on the night.

1. Start with what you want and why, not with rules. "I miss feeling wanted" opens a conversation; "I want to see other people" can close one.
2. Say what you are afraid of. That you'll hurt them, that it will change things.
3. Don't ask for an answer on the spot. Give your partner time.
4. Expect any answer. Including no, and including questions about whether something has already happened.
5. Get help if you need it. Relate offers couples counselling and sex therapy, and a counsellor can help you both say difficult things safely.

An example of how you might open the conversation, to put in your own words:

"There's something I've been thinking about for a while, and I'd rather talk about it with you than keep it to myself. I don't want an answer tonight. I just want us to be able to talk about what we both want, honestly."

If something has already happened, be honest with yourself about whether the open-relationship conversation is really a way of seeking permission after the fact. Your partner may well see it that way. Our guide to getting support explains counselling on your own first, which many people find useful before a conversation like this.

If the answer is yes: agreeing the rules

A yes is the start of a conversation, not the end of one. Before anyone meets anyone, most couples agree:

• what is allowed and what isn't, physically and emotionally
• how much each of you wants to know, and when
• protection and testing, and what happens if a condom fails; NHS sexual health clinics are free and confidential in the UK
• how to pause or stop, and how much notice that needs
• when you will next sit down and review it

Write it down if that helps. Rules that are only implied tend to be remembered differently by each person.

When an open arrangement starts to feel like an affair

Open arrangements can drift. The signs are usually small at first: a rule quietly broken, a meeting not mentioned, feelings for someone that you would rather your partner didn't see. Once one partner is keeping things back that the agreement says should be shared, the arrangement has started to work like an affair for the person at home.

The fix is the same conversation that set it up: sit down, say what has changed, and agree again, or agree to stop.

Being clear with the people you meet

On Marital Affair, members are married or attached, but their situations differ. Saying which applies to you saves a lot of misunderstanding.

• Say on your profile whether your partner knows.
• Ask the people you talk to the same question, and respect the answer.
• If someone is in an open relationship and you are not, be honest about that; their partner has agreed to them seeing someone, not necessarily to the risks of an affair.

Whatever the arrangement, the same ground rules apply. See setting boundaries with someone you're seeing and sexual health with a new partner. For what the site shows other members, see our discretion page, and for the wider picture of who uses these sites, married dating explained.