Polyamory has existed across time and space – monogamy and the nuclear family partially developed in response to the capitalist system – but a modern, more annoying kind now plagues the dating apps of British cities. Whether or not you’d enter into a relationship like this yourself is one thing, but getting involved with someone who already is presents a whole different challenges, with fewer advantages.

All of my own brushes with non-monogamy have been a far cry from the utopian ideals many of its proponents claim it represents, and poly people are, with the best will in the world, kind of insufferable. For example, Neil Gaiman and Amanda Palmer, the two least cool people in living existence, have an open marriage. If that alone isn’t sufficient, here are some further reasons why dating someone who has a partner might be a terrible idea.

You’re Unlikely To Be Their Priority

There’s a Lana del Rey-esque glamour to the idea of being, in effect, someone’s mistress, but the reality of knowing you’ll never be their number one concern can be upsetting. The terminology of ‘primary partner’ itself implies that you are secondary. Why would you settle for that?

No piece of art has captured the pain of this situation better than Nina Simone’s “The Other Woman.” I used to listen to it when I was seeing a guy in an open relationship, and would heavily relate to lyrics such as “the other woman has time to manicure her nails, the other woman is perfect where her rival fails” while I was sitting in my house-share in a pair of grubby trackies, drinking a can of Tyskie.

The point is: you might be the exciting one; the one who still sees them as fresh and remarkable, and makes them feel that way; you might have better sex together, but if they’re with someone else it’s because they have a larger emotional commitment and shared history. It’s difficult to compete with that. As Nina tried to warn us, “the other woman cries herself to sleep, the other woman will never have his love to keep.”

What if you catch feelings for this person? What if you decide you want to move to Hove with them and rescue a dachshund together? Well, you can forget Hove, and you can forget your precious little dachshund, too – it’s not going to happen. They’re probably not going to leave their partner for you. The whole point is that you shouldn’t want them to but you might find that your innermost yearnings aren’t as progressive as your politics. And then you’re fucked.

Be Prepared for the Fact That Their Partner Might Hate You

There’s a big difference between getting cheated on and your partner sleeping with someone else with your consent. In the former case, the sting comes from the dishonesty – the sense of a contract having been breached, rather than the physical act. This is actually a pretty good argument in favour of non-monogamy: there’s no reason to feel hostile towards someone your partner is having sex with. But nonetheless, it’s not uncommon for hostility to arise.

Jealousy and possessiveness are ugly things. The question of whether they’re innate, owing to some biological impulse, or socially constructed is irrelevant: we can agree they’re harmful qualities we’d be better off without. The goal of non-monogamy is to transcend all this, which is laudable but not always realistic. Not everyone, and certainly not everyone in a non-monogamous relationship, has the self-possession to say ‘jealousy is bad, so I won’t be jealous.’

If you start seeing someone with a partner, then, their partner might end up hating you. It’s up to you to decide whether that’s something worth caring about.

Or Their Partner Might Try To Be Mates With You, Which is Weird

At the other end of the scale, they might treat you with great kindness and generosity of spirit, which is obviously infuriating. Listen, I appreciate the invite to your dinner party, or jumble sale, or orgy, but you should consider me a threat, sweetie… I find your smug complacency insulting.

If I’m fucking your partner, I would rather our interactions were kept to a minimum. In a New Statesman article on the subject, Laurie Penny writes that polyamory means "sharing Google calendars to make sure nobody feels neglected." While that does sound both erotic and very fun, I don’t want to have to open a spreadsheet every time I feel like getting my dick wet. Please never send me a Google doc invitation.

The Break-ups Are Just as Messy

The first open relationship I had began, as they often do, as a last-ditch attempt to save a relationship that wasn’t working. My partner insisted that there were to be no rules, other than telling each other when we slept with someone else. We could go on dates, see the same person repeatedly; nothing was off-limits.

This backfired for him. Not long after, I met someone else who treated me a lot nicer, and I ended the relationship. It worked out well for me: non-monogamy provided a route out from what was, I can see now, a terrible relationship. But for my new boyfriend, it was a nightmare: not only did he have my trauma to deal with, but my ex began trying actively to sabotage our relationship.

I realise that the takeaway lesson from the above is ‘abusive men are abusive’ rather than ‘non-monogamy is bad.’ But it does illustrate that non-monogamous relationships aren’t magically immune to violence or jealousy. Poly people don’t exist on a higher plane of consciousness, as much as many of them appear to think so. Their relationships don’t exist in a utopian vacuum, either, they are just as susceptible to dynamics of subjugation. I’ve heard countless stories from women of men they’ve been involved using polyamory as a form of coercion, simply another means of getting what they want; namely, sex.

If you get involved with someone in a relationship and that relationship goes wrong, the fall-out can still be horrible, no matter how enlightened everyone involved thinks they are.

The Rules! The Endless Rules!

I can imagine the objections of non-monogamous people as they read this. "Ah," they’ll bleat, "all of these problems are about a lack of rules! If you simply drew up a rigorous enough code of conduct, then none of this would be an issue." But why should you have to adhere to other people’s – often highly idiosyncratic – relationship dictums? When you weren’t even privy to that discussion?

They also say things like "non-monogamy is great because it lets you figure out what’s right for you, rather than just blindly following a relationship model handed down from society :)" This might be true if you’re in the relationship itself, but if you’re a third party then the rules become tedious: ‘We can have sex but you can’t stay over,’ ‘You can come to my flat but only on the second Thursday of the month,’ ‘We can go for breakfast or lunch, but not brunch.’

The endless compromises and discussions of non-monogamy can end up feeling just as restrictive as monogamy, with its one easy-to-remember rule of ‘don’t fuck other people.’ If you're not careful, your 'ménage à trois' might end up more like a 'ménage à blah, blah, blah!’

Polyamorous People, As Previously Stated, Are Annoying

Having sex with lots of different people is fun, so it’s strange that a movement based around it is is so dull. There’s a vein of worthy smugness amongst people who are into polyamory; the sense that they, the enlightened few, have figured out a secret everyone else is too dim-witted to grasp. I’m not saying every poly person is like this – that would be a ludicrous generalisation – just most of them.

Polyamory, as a concept with an attendant culture as opposed to the idea of non-monogamy itself, is also just...kind of lame. It’s for people who pay £800 to live in a warehouse where having a cleaning rota and doing a big shop together is considered a radical reimagining of communal living; people who smugly identify as ‘perverts’ because they tried rimming once and imagine that reclaiming the term is empowering; people who really, really want you to know they’re not a virgin.

Polyamory exists at the point where self-described radicalism becomes gratingly twee. It’s a widely known fact, for instance, that every poly person likes Dr Who. Do you really want to get your heart broken by someone whose Tinder anthem is ripped from the Juno soundtrack?

As well as the unwarranted smugness, there’s a sense of equally unwarranted victimhood. The existence of a polyamory pride flag suggests a parallel between the queer experience, while other poly people have attempted to have it recognised as an orientation in itself. I realise plenty of queer people are polyamorous – we arguably popularised the idea – but is polyamory queer in itself? Not really. Has anyone ever been oppressed purely on account of being polyamorous? I only heard the term ‘vector of oppression’ for the first time a couple of weeks ago and I’m still not sure what it means, but I’m going to go ahead and say, with complete confidence: no, being polyamorous isn’t one.

Laurie Penny, in the same article mentioned above, writes that "we [polyamorous millennials] want fun and freedom, but we also want a good mark in the test". So there you have it – polyamory is for nerds.

Right. In conclusion: every problem with non-monogamy has its counterpart in monogamy which is, I’m afraid to say, also not great. So if you meet someone in a poly relationship and you like them, if the sex is good and they’re kind, I’d say go for it. Maybe… it’ll be fine? But although the problems outlined above are by no means inevitable, they’re not uncommon either. If you’re considering entering into arrangement like this, they’re worth considering, because polyamory is not a panacea to all the agonies and contradictions of the human heart. It’s also, by and large, for steam punks.