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Everyone in a long-term relationship is likely to experience at least one time when they just don't feel like having sex and so turn their more amorous partner down.

It's a long-held belief that it's usually women who don't really fancy a session at the end of a long day - but new research has shown that actually, men can be just as likely to 'have a headache' as their partners when they've been with the same person for a long period of time.

Researchers at the University of Kentucky analysed 64 studies on sexual desire between couples that go as far back as the 1950s and reach as far as the present day.

They found that contrary to popular belief, guys are typically first to lose interest in the physical side of things when they've been with the same person for some time. Even more interestingly, this was particularly the case when they were unhappy or insecure.

It just goes to show that the old received wisdom about men being 'up for it' all the time and able to disconnect their emotions from their body absolutely aren't true.

What's more, society today could be more likely to put men off sex even if they had a healthy appetite for it before. This is because they're being led to believe that they should be aroused at the flip of a switch and that there is something wrong with them if this isn't the case or, heaven forbid, if they'd rather just watch Netflix tonight, thanks.

Writing in the Journal of Sex Research, the study authors explained that many men expect their sexual appetite to stay at the same level it did when they were a) younger and b) in a brand-new relationship - and when it doesn't, they grow exasperated and can be put off sex altogether.

Other factors involved were a lack of emotional connection and fear that their partner finds them unattractive, demonstrating just how important that sentimental bridge between two people is in the long term.

When the men in the study did have a strong level of emotional intimacy with their partner, they were more likely to want to sleep with them.

Lead author of the study Kristen Mark said: "We expect male desire to always be high and to be simple ... while we expect women's desire to be a complicated switchboard, but they are both complex. Research in recent years has clearly shown that these gender-based assumptions about sexual desire are not supported by data."

Sex in a long-term relationship can be easy to neglect, especially as you make the transition to what marriage therapist Gary Brown told SELF magazine is compassionate love as opposed to passionate love.

To keep the spark alive, he recommended sitting down for ten minutes to talk and really emotionally connect with your partner each day; ditching phones for one evening a week; and imagining that each time you make love is the last time.

The last one is slightly morbid, but we get what he means: remember that to love each other physically, you need to remember why you love each other's minds.

And don't forget that sex toys might help if you're stuck in a rut, too. What do you think? Have you got any tips for making it work in the long term?