Monogamy is the foundation of modern relationships. But it hasn’t always been that way.
Keys in the bowl, polyamory, threesomes … you’ve probably heard the words whispered somewhere between Married at First Sight and your group chat. But what if I told you one in five people has actually tried consensual non-monogamy?
Monogamy is the foundation of modern relationships (happily ever after, till death do us part). But it hasn’t always been that way. Many ancient societies embraced non-monogamy as normal. And while monogamy is the acceptable norm in 2025, the alternative – consensual non-monogamy (CMN) – is far more common than you might think … and is steadily gaining in popularity.
If it’s not consensual, it can go in the bin. The first type of non-monogamy I have to mention is infidelity. It’s the version we hear about most often - seedy secrets splashed across the pages of glossies – but that’s not what we’re talking about here. Add the word consensual and the dynamics change completely. Now it’s about honesty, agreement and ethics.
CNM can take different forms, including (but not limited to):
· Polyamory - having romantic and/or sexual relationships with more than one person at the same time, with everyone’s knowledge and consent.
· Swinging - couples consensually swap partners or engage in group sex.
· Open relationships - the primary partnership remains, but partners are free to connect with others in agreed ways.
You’ve no doubt heard stories about open marriages, or the fabled “keys in the bowl” parties. But consensual non-monogamy is more popular than people realise.
US estimates show that up to 5% of people are currently engaged in consensual non-monogamy, and that up to 20% of people have tried it at some time. That’s one in five. So take a look around the room, and do the math …
Fantasies go even further. Research shows that threesomes are the most common sexual fantasy for both men (95%) and women (87%). So what is it about the magic number three that makes it so widespread and appealing? Studies suggest that it’s the heightened arousal created by the thought of having another person to explore and experience sexually, and the activities you might engage in with two people as opposed to one. The particular partners and setting don’t seem to matter so much.
And if that’s not your flavour, so to speak, you’re not alone, but curiosity is clearly widespread. What’s that old saying – don’t knock it till you’ve tried it?
Attitudes are changing, too. Younger generations are much more open-minded, due in part to wider acceptance of gender and sexual diversity, and believe that open relationships may be a way to explore their identities and desires. One survey found that over half of 18–29-year-olds say that open marriages are acceptable, compared to far fewer older respondents.
Well … not necessarily. As it turns out, relationship satisfaction and sexual satisfaction in CNM relationships are no different to monogamous relationships. In other words, it’s not better or worse, it just depends on the people involved.
From my experience, it runs the gamut. Some people make it work incredibly well, some discover it’s not for them. The unsexy truth? Trust, respect, intimacy and effective communication are what make it or break it. And if those foundations aren’t solid, opening things up probably won’t fix them.
But, when couples do enter into CMN with honesty, understanding and respect, I’ve seen some of the happiest, most deeply committed relationships around – often with an added sparkle in their eye, or spring in their step.
As for those “keys in the bowl” parties? Yes, they really do exist. Keys may not always be swapped, but partners certainly are, and from all reports, the people throwing their metaphorical keys in the bowl are having a lot of (orgasmic) fun.
It’s healthy to accept (rather than repress) our fantasies and realise that in the main, they are probably very normal things that a lot of people fantasise about. Discussing your fantasies with your partner builds trust and can strengthen your relationship and improve intimacy and desire for your partner.
Research shows that couples who discuss their fantasies with their partner have the happiest relationships and the most satisfying sex lives. It’s certainly a great way to spice up a relationship in which sex has otherwise become stale or boring. And if your partner shares your fantasies? Well, you might just find yourself happily adding your keys to the bowl.
If you’re curious about CNM, the first step isn’t a hall pass. It’s an open and honest conversation with your partner. It might feel daunting, but openly talking about your desires is essential.
While it’s possible that your partner may have a negative reaction, the largest study ever undertaken on this topic found that most people who discussed their fantasy of group sex or non-monogamy had a positive reaction from their partner. Thinking about your partner’s personality and sexual history will give you some insight as to how they may react – for example, are they prone to jealousy, have they enjoyed casual sex before, do they generally like to try new things?
Taking small steps and slowly discussing things over time can be an effective way to help your partner consider a new idea. And remember that this is a two-way street – as you share your fantasies with your partner, they will likely share some of their fantasies with you.
It’s important to think about the timing and the setting before starting this type of conversation – you don’t want to shock your partner in a public setting. Make sure it’s an appropriately private setting, free from distractions. It’s also important to consider your partner’s feelings, to reassure them of your trust and love, and to validate them. Make it clear whether this is purely a fantasy, or something you may wish to try. If it is something you do want to act on, don’t expect to go rushing into it. It will likely take some time for your partner to get used to the idea, and you will need to build trust, and lay the foundations and boundaries.
And if your relationship is already rocky, fix those foundations first, because CNM won’t be the magic answer.
Fostering an environment where you can share your feelings, desires, and fantasies is key to any satisfying relationship. Even if it doesn’t go further, simply opening up can make you feel closer, and you might just discover your partner has been thinking about the same thing.
Rachel Strevens is a sexologist, sex coach and educator, and founder of The Passion Project. She is also the creator of Ignite: Passion and Pleasure, New Zealand’s first event dedicated to women’s health, confidence and pleasure. Find out more at passionproject.co.nz