Seven signs your partner fancies your friend: I'm a relationship counsellor and this is how to spot a harmless crush that could escalate

It is perfectly normal for the man in your life to find your friends attractive — and it is equally acceptable for you to secretly fancy the other men in his life.

But as a psychotherapist and relationship counsellor I have worked with plenty of couples who found a seemingly harmless crush has escalated to create tension, conflict and has even led to affairs and new relationships which spelt the end of their marriages. My advice is to keep an open mind and to trust the bonds that brought you and your partner together in the first place.

However, pay close attention to your instincts and if some aspect of your relationship has changed or doesn't feel right, and you suspect your partner's feelings for one of your friends may be intensifying, look out for these signs that things may be spinning out of control — and read what to do about it...

He starts to criticise her

Listen out for repeated mentions of her name — even in a negative context. Listing her annoying habits and exclaiming with mock irritation 'Can you believe what she's doing?' could indicate that temptation is brewing. The 'tell' is a disproportionate awareness that seemingly comes out of nowhere and his temptation to relate stories about her with super-charged detail could be a sign he's becoming obsessed.

Keep an eye out for social plans that happen when you're busy or engaged. When their get-togethers always seem to be without you, you may have reason to be suspicious

She lights his world

A polite and pleasant demeanour around your friends does not mean your partner is harbouring fruity fantasies, but watch for extremes: one minute he's disengaged and vacant but then lights up with giddy excitement when she walks into the room? You could have a problem.

He acts the hero

It is the job of a partner or husband to be more attentive to you than anyone else, so red flags start waving if he becomes super-helpful around a friend, leaping in to rescue her from disaster and curating an exhaustive solution for a potentially tricky life issue. Huffing and puffing about helping out your friends can sometimes be a very good thing!

If he starts to work harder at the gym or takes great pride in a new haircut it could be a sign he wants to show off to someone who he wants to take notice

Makes plans when you're not free 

Keep an eye out for social plans that happen when you're busy or engaged. You can put once or twice down to coincidence but when their get-togethers (even in a group) always seem to be without you, you may have reason to be suspicious.

He shows empathy

If he fancies one of your friends he might try to disguise his attentiveness but unwittingly express empathy for her if she is having difficulties. This can show he is losing perspective. Look out for scenarios where he's relatively unsympathetic.

Smartens up his act

This one is a cliché for a good reason. If he starts to work harder at the gym or takes great pride in a new haircut, you can be forgiven for wondering who he's dressing up for. It could be vanity or a sign he wants to show off and there may be someone in mind who he wants to take notice. Inspiration and motivation so often come with infatuation.

He gets grumpy

If he's seriously crushing on one of your friends, he might get withdrawal symptoms when he's not in her orbit and he might take his frustration out on you. Trigger phrases include 'She's so easy going, why can't you be more relaxed?' or 'It wouldn't hurt to dress up sometimes'. Comparisons could be a sign that he is starting to idealise her.

...Here's what to do

Even if you spot these signs, it is only a hunch so it would be a mistake to assume you know how this is going to pan out. My advice is to stay alert but wait to see if anything emerges. Your best move is to bide your time and, if something is going on, to allow them to reveal themselves and expose their betrayal.

Charlotte Fox Weber

As told to Louise Atkinson @charlottefoxweberpsychotherapy