‘If three people love each other and agree to enter into a committed, sexual relationship with each other, what’s wrong with that?’

Responses vary, but laughter is probably the most common response. Some laugh because it’s something they think is so unlikely it’s comical. Others laugh because they feel a bit nervous, unsure of how to answer.

But it’s a question I think we Christians – and certainly Christian leaders – need to start thinking about, because it’s a question that will be coming up a lot more in real life in the coming years.

The rise of polyamory

The relationship envisaged in the question is an example of polyamory – a romantic and sexual relationship between three or more people with the consent of all involved. It would also be an example of consensual non-monogamy ­– a broader category encompassing any sexual relationship where those involved agree the relationship is not exclusive.

Polyamory and consensual non-monogamy will almost certainly be the next step in western society’s journey away from traditional, Judeo-Christian-rooted sexual and relationship ethics. While perhaps still a fringe practice at the moment, acceptance and practice of polyamory and consensual non-monogamy are on the rise.

The last few years have seen an increasing number of polyamorous and consensually non-monogamous relationships being portrayed in popular media. Shows such as the BBC’s Wanderlust and Trigonometry and Channel 4’s The Couple Next Door centre on such relationships, and popular shows like Netflix’s Sex Education and Australian soap Neighbours have featured polyamorous characters or relationships. This year there has been a significant increase in media coverage of the topic (see Polyamory in the News). And this month saw ‘Week of Visibility for Consensual Non-Monogamy’.

This all matters and is likely to have a considerable impact. Ask that discussion question – ‘What’s wrong with a three-person sexual relationship?’ – of most people in the modern west today, and they might first respond with an instinctive distaste for the idea, but push them on why and they are unlikely to be able to defend their position. For those familiar with Jonathan Haidt’s work, this is people’s elephant’s (their intuitions) reacting and then their rider (reason) becoming a PR person trying, but struggling, to defend the elephant’s direction of travel.

Most secular people won’t have any convincing arguments against polyamory (even though there actually are some – monogamy is good for both society and individuals, especially women and children.¹) And because they don’t have good arguments, the visibility of seemingly healthy and harmless polyamory that brings happiness to those involved will begin to change people’s perspectives. To think in Haidt’s terms, the visibility of polyamory will appeal to the moral intuitions most prominent for many modern westerners (care/harm, liberty/oppression, fairness/cheating) and that will change the direction of people’s intuitions – their elephants. This is why it seems pretty certain that polyamory and consensual non-monogamy will grow in acceptance and practice, possibly quite quickly.²

Now is the time

That means now is the time that Christians need to be thinking about polyamory. If we’re honest, many of us might find we’re currently quite like our secular neighbours: We instinctively sense that polyamory and consensual non-monogamy are wrong. We can probably take the extra step of saying ‘Because the Bible says so’. (Although could we then defend that claim well? And what do we do with the practice of polygamy in the Old Testament?). But many are likely to get stuck at that point.

Because of this, many Christians will be susceptible to being swayed to acceptance (just as we’ve seen with same-sex sexuality), and many will be ill-prepared to communicate God’s good plan to the world around us.

The Christian opposition to same-sex marriages is currently often one of the biggest barriers to people considering the Christian faith. In a decade or so, our opposition to polyamory could be another big barrier. Will we be ready to help clear that barrier so people can consider the claims of Jesus?

I think this is an important moment for Christians. I also think it’s a moment of opportunity. We have the chance to get ahead of the curve, to work out what we believe and why now, before we’re having to explain and defend that. We have the chance to learn from some of the mistakes in our past handling of sexual ethics (for example, in the same-sex sexuality conversation), so we can do better at loving people in this conversation. And we have the chance to prepare to engage well on this topic, not just playing catchup and trying to defend Christian teaching, but showing people how God’s plan for sexuality and relationships is good for all of us and how it is in the gospel and God’s way of living that we can find the best answer to the desires often driving the practice of polyamory.

‘What’s the problem with polyamory?’ At the moment, our problem may be that we don’t really know. Now is the time to ask that question for ourselves, because soon enough, we’ll have other people asking it of us.

To help jumpstart the Christian conversation on polyamory and consensual non-monogamy, I’ve written a short booklet titled Three or More: Reflections on Polyamory and Consensual Non-monogamy (Grove, 2024). In the booklet, I talk about how society has got to this point, how we can engage well with biblical teaching and with arguments in favour of polyamory, and I give some pointers to start our thinking about a Christian response. Get your copy now.