Years ago, my best friend fell in love with a man I disliked. He had a habit of looking over my shoulder when I tried to talk to him, and I thought he was too possessive. He spoke to her using a special high-pitched baby voice, and the worst thing was that my friend absolutely loved it, and would baby-talk right back. Thinking that our friendship was bound to outlive her infatuation, I made it obvious that I disliked him. I very pointedly made plans without him, and when I was forced to spend time in his presence I made so many private jokes I was essentially talking to my friend in a horrible baby language all of my own.

To no one’s surprise but mine, this behaviour didn’t have the desired effect. My friend started avoiding me. Her boyfriend won and eight years later he’s still winning. They are getting married next year, and I am not invited.

Disliking a friend’s partner is such a common experience, but it’s hard to know what to do about it. Experts agree that if you suspect that your loved one is at risk of physical or emotional abuse from an intimate partner, you should let them know that you’ve noticed something is wrong. But what if your friend isn’t in danger, and you just feel their other half isn’t worthy of them? What if he makes sexist jokes? Or worse, he’s really into nutrition? What if he traps you in long, intensely detailed conversations about his triathlon training and breathes exclusively through his mouth?

In the past, my tactic has been to simply avoid asking my friend about their relationship at all. I’ll refuse to say the hated partner’s name out loud, as though I am a wizard and the partner is Lord Voldemort. I also have a trick where I pretend I need the toilet every time I’m stuck talking to the partner in a group setting. But none of this behaviour is particularly subtle, and I’d like to find a more constructive way of coping with the situation. In the interests of doing things differently, I spoke to therapists and relationship experts about what to do when your friend loves someone that you really don’t.

Ask yourself, why do you dislike this partner?

The psychotherapist and conflict mediator Gabrielle Rifkind suggests that when you notice yourself turning against a friend’s partner, you should try to unpack those feelings. Rather than assuming that you are entirely justified in your dislike, “we should look inside ourselves and think, why are we having difficulty? Maybe we fear they will take our friend away from us,” she says.

If you think your friend’s partner has no sense of humour, for example, it’s worth asking yourself why you find that so threatening. Are you worried your friend will change and stop finding you funny? “If you fear loss, you can have a conversation with your friend and ask them: ‘How can we take care of our relationship as well?’” says Rifkind. Arrange a regular phone call with your friend and then you might not feel so hostile towards their partner. You may be lashing out because you fear being replaced.

If you are single or in an unhappy relationship, there’s also a chance you could unconsciously be jealous that your friend has found love. Perhaps the partner’s tendency to cling on to your friend’s hand on nights out isn’t actually a sign of his devious and coercive nature? Maybe it’s a sign of his sweetness and devotion; it’s just that you’ve warped it all in your jealous mind (I have sadly been guilty of this). “We have got to look at our own motivations, because that is where we can change things,” says Rifkind. “We can’t change other people’s behaviour, only our own.”

Grit your teeth

“We live in a culture that prizes honesty, but sometimes sensitivity is more important,” says Rifkind. Even if your judgment isn’t clouded by jealousy and insecurity, and this partner truly is a dud, it doesn’t follow that you have to inform your friend of that fact.

If you tell your friend you don’t like their partner, “you put them in an impossible position where they have to choose between you”, explains the psychotherapist Chris Mills. “The best thing you can probably do is live with the dislike.”

Mills points out that some of the faults that seem so heinous to you might actually be what attracted your friend in the first place. If a friend’s new girlfriend is loud and obnoxious, for example, it may be that your friend is frustrated by his own quietness and introversion, and admires her ability to stay silent or make her displeasure known. Mills says that even if your friend really is making a mistake, and will live to regret the relationship, it’s best to allow them to find that out in due course. “Maybe somebody else can’t rescue them from that mistake. They have to rescue themself.”

Try to forge a relationship with the partner

Time with friends can feel so precious that we get selfish about it, and want to indulge in shared jokes and references, but this will exclude a new partner and put them on the back foot. Rather than expecting the partner to slot seamlessly into an existing dynamic you have with your friend, it’s up to you to step out of your comfort zone, and get the partner talking about a subject they are interested in.

“Be sincere about wanting to know more about them,” advises Rifkind. Ask questions about the partner’s interests with an open mind and a real wish to know more, not simply out of a sense of duty. “Go on a journey trying to find out all about them,” says Rifkind. Who knows, you might surprise yourself. Maybe you have a latent passion for nutrition, too?

Organise one-to-one hangouts with your friend

If you have attempted that sincere journey with your friend’s partner and it turns out that you still don’t get on, remember you don’t actually have to spend that much time with them. “The first thing to acknowledge is that their partner isn’t your partner. You didn’t pick that person, and can certainly engineer events where you are one-on-one with your friend,” says Jaimie Krems, director of the UCLA Center for Friendship Research.

You will probably have to endure the partner at your friend’s birthday, but with enough careful planning, and without ever hinting to your friend that you don’t like their partner, you might actually be able to get away with only seeing them once a year. “You can be a little bit sneaky about it if it’s not harmful,” says Krems. “So if your friend’s partner hates paint-your-own-pottery you can do that with your friend.” It could be worth doing a little covert research into the partner’s least favourite films, musical artists and sports – and then block-booking tickets for the next five years.

Blow off steam to another trusted friend

“Moaning and griping is terribly important,” says Mills, who advises venting about the partner as a way of dispelling some of your pent-up negativity. “Have a word with other friends. I don’t think that’s unhealthy – but I think you have to be careful when choosing who those other friends are.”

Talking to someone who knows your friend is a bad idea, says Mills, because it will stir up more ill will towards the partner within the friendship group and fan the flames of your dislike. But if you can find someone who doesn’t know any of the people involved but is willing to listen to you complain viciously about a random stranger, let rip. “We need to let go of some of that stuff,” Mills says. “It’s just about deciding where you let go of it.”

Can’t help voicing your dislike? Prepare for your friend to hate you right back

Perhaps you feel that the lack of honesty between you and your friend is corrupting your relationship. Or your friend is about to have a child with someone truly awful and you genuinely think she might not if you offer a few well-placed critiques. If you feel you can’t live with yourself without telling your friend the truth, you must be willing to suffer the consequences.

The friendship researcher and sociologist Janice McCabe says that we can have short, intense friendships – but we can also have “long-term friendships that typically become closer and further apart over time”. If your relationship with your friend falls into the second category, you could tell them that you worry they are making a mistake, “but you have to accept they may need some space from you afterwards”, says McCabe. Perhaps your friend will mull over what you have said, magically realise that you are right, and dump her boyfriend. More likely, she will still get pregnant and freeze you out of her life for the foreseeable.

Maybe the best thing to do is to remind yourself that your friend might not be so easy to love, either. All her boyfriend’s friends might, at this very moment, be discussing how dreadful she is, and plotting the best way to set him free. If you don’t like him, the likelihood is they don’t like her. Perhaps her boyfriend deserves your sympathy. He might be making a terrible mistake, too.