We are constantly assailed by news of other people's sex lives. If it's not the reinvention of model Christine McGuinness as a 'five-star lesbian', it's a new series of Virgin Island on C4, in which people who've never had sex are given 'lessons' on national TV.

Meanwhile, actor Kate Winslet and national treasure Prue Leith gush about the benefits of testosterone to boost a flagging libido.

It's hard not to feel like you're letting the side down if you're not hitting the UK's golden average and having sex once a week.

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And I certainly wasn't – until my partner and I found a radical solution: we split up without splitting up.

It's undeniable that after a certain amount of time with the same person, sex can lose its oomph. I've always thought desire thrives best without too much expectation, particularly at the ripe old age of 52.

Sexologists tend to diagnose boredom and prescribe a menu of sex toys or the exchange of long-held fantasies over dinner – but for most of us, that's not why it happens.

In fact, it's something far more prosaic: it's mutual grumpiness. It's the tutting when you use the butter knife in the jam. The loud, passive-aggressive rearranging of the dishwasher. The irritated sigh at the sight of dog hair on the sofa cushions.

It's getting the hoover out for crumbs before you've finished eating your breakfast toast. The angsting over visits by admittedly messy friends of your teenage children. The peevish re-drying of wine glasses because you smeared them as you put them away.

It is, in short, the everyday annoyances and resentments that arise in a long-term relationship where housekeeping habits are fundamentally misaligned. For nothing kills a woman's sexual desire quicker than a husband who wafts Pledge more than he does eau de cologne. Who genuinely thinks that there is a 'correct' way to slice unsliced bread.

I have been with my partner Mike for nine years and he has many positive attributes. He's funny, caring and a big lover of life. At 43, he's still eminently fanciable but, like many contemporaries, we sometimes find ourselves irritated with each other.

In our case, traditional gender roles are reversed: I am the one who leaves the mug by the side of the sink while he internally seethes, for example.

He is the one whose midlife crisis is apparently manifesting as a bad-tempered bout of spring cleaning.

Any and all domestic issues can cause an outbreak of bickering. When I move a phone charger, he reacts as though I've caused a rift in the space-time continuum. When he tells me a car should always be reversed into a driveway, I roll my eyes like a teenager.

I try not to put my slippers on the sofa – even though they're indoor footwear, doh! – but occasionally can't help myself and he'll look pained and might even audibly groan.

Having a pair of eyes watching your every move as you plough your way through chores elevates the nervous system until you're constantly on a hum of alert. I'm not talking about a couple of eyebrow raises either – we're talking 30 to 40 times a day.

I'm already clumsy. If I feel like I'm being assessed when drying a plate, I know the plate will slip from my hands. If I'm handling a wine glass, it's more likely the stem will break.

I'm sure it feels like the same level of stress and unease for him.

We still have many common passions – hiking, cooking, our dog Stella – but thanks to our mutual annoyance, the Grand Passion has almost gone.

Or it had. For I have found the answer to the waning of our sex life. The solution to our mismatch in attitudes to housework and his low-level grumpiness. Two houses – one for him, where all is spick and span, and one for me where the dog is allowed on the sofa.

It's amazing how quickly you regain respect – and the hots – for someone when they're not forever telling you off.

Almost a decade ago, in the throes of early romance, we bought a wonderful 1920s house together in Northamptonshire. We'd met the old-fashioned way in a pub, in real life.

The signs weren't auspicious at first: he was on a stag do and dressed as a 'sexy' nun, wearing stockings and badly applied lipstick. I was previously married, had two children and wasn't looking for romance with a bloke in a habit.

But boy did we hit it off. After making me laugh all night, I thought this has legs – and he continued to make me laugh for the next nine years.

The point is, we are perfectly compatible when not on home turf.

The problems only arise when we live in the same space. It all came to a head a year and half ago just before Christmas, when a planned family get-together proved too much for Mike's turbocharged tidy streak.

The older we've got, the more our housework habits have diverged and the thought of my grown-up children, then 23 and 19, one of their partners, a grown-up niece and assorted others 'ransacking the house', as he put it, and the chaos it would cause, was clearly too much. Mike sought refuge at his mother's on Christmas Eve and left me to the noise and mess that we all know comes with a family.

Afterwards we both knew we couldn't carry on living like that. I felt sad that he couldn't sit on his hands for two days and go with the festive flow and he was cross with me for not 'getting it'.

The easy route would have been to split up there and then, but the real fly in the ointment was that we both still loved each other.

When he wasn't crossly dusting the dining room table, he was the best company in the world. I didn't want to stop being his partner; I just wanted to stop annoying him at home and vice versa.

Once upon a time, most people got married before they lived together and only discovered irritating habits once there was no going back.

Then they often didn't bother with the marrying part and just lived together, which was less permanent but still meant the rose-tinted spectacles came off and never went back on.

Now we're not even living together. About 10 per cent of all heterosexual couples of all ages in the UK live in different households while having a steady intimate relationship with each other. A new study conducted by Lancaster University and University College London, shows that this unconventional arrangement seems to work especially well for older couples.

I spoke to one of the study's authors Dr Yang Hu who reassured me that Living Apart Together (LAT) is more common in midlifers like us than you think.

'Many people think that Living Apart Together is just for young people. But our findings show that it tends to be a stable, long-term form of relationship among older adults,' says Dr Hu.

'We should recognise the strength of the often invisible and intimate ties beyond the household in sustaining older adults' wellbeing.'

Before our split that isn't a split, I'd rarely spent any time alone.

I haven't been single for more than three months since I was a teenager and have lived with each of the men in my three long relationships.

Maybe it was time I did spend some time on my own. As the author Paul Coelho said: 'If you're never alone, you cannot know yourself.'

But early this year, when a lovely rental owned by a friend in a nearby Northamptonshire village suddenly became free, it felt like a sign. We would trial an LAT arrangement and see what happened. If it worked, we'd sell our house and find a way to each buy something smaller.

There was another potential benefit to this, which again only really occurs in midlife. His mum lives on the south coast while mine is at the other end of the country, on the north-east coast. It was always going to be a logistical conundrum with increasingly elderly parents.

The day I moved out was undeniably sad. You don't 'leave' when a relationship is working, do you?

He helped me move into the cottage and then I waved goodbye as he went back to our house a 20-minute drive away. Was this the end? We've been told for so long that living alone equals being lonely, it seemed like a backwards step – no matter that I knew it was the only way we could stay together.

It wasn't always easy and it wasn't cheap to run two places either but spending time apart was a revelation.

We missed each other. Properly. But not enough that I wanted him there all the time. Nor he me. In fact, being alone often felt utterly joyful. I played the piano more. I watched documentaries instead of the Jason Statham films he wanted to watch.

I'm an early bird and now I could get up at 6am and not have to tiptoe around for hours like a ninja. I revelled in the freedom to come and go without feeling duty bound to let anyone else know where or when I was going – though I did miss a live-in dogsitter.

We're busy people – he's an accountant, I'm a freelance writer – and the time flew by without being punctuated by arguments over silly household stuff. I could come home and chuck my shoes on the hall floor without lining them up neatly or putting them away. The dog could sit with me on the sofa. In the first six months we saw each other a handful of times a month and were excited when we did.

Yes, our sex life improved immeasurably. And we both loved having our own beds, too (mine casually made; his with hospital corners). Honestly? It felt like dating again.

He made more effort when he saw me, we both talked to each other and looked at our phones less and, crucially, he didn't complain about how I cut the bread.

With less criticism we liked each other more and we were more intimate, because essentially there was more respect for each other. We're told cohabiting is the natural progression of things but for some people, it really isn't.

We've now been living separately for almost a year and will soon be renting our house out so that he can get a rental of his own nearer his mother. A few months into our experiment, she had a nasty fall and badly broke her arm, and he wants to be able to get to her quickly if needed.

I know some people think our relationship is unusual. When I talk to friends, I'm surprised by the number who've never thought living apart is an option, even when living together isn't working.

But one thing's for sure. Living apart has meant more sex, more happiness and the almost complete end to domestic bickering.

Unconventional yes, expensive also – but if you're hankering after a revved-up sex life after years of sorry decline, here's my tip. Move out.

• Mike's name has been changed to protect his identity.