I was mortified when my husband always said no to sex. Then I realised the mistake I was making. This is the change that's completely transformed marital love-making in middle age: ALICE SNAPE

If I waited for it just to happen, I might never have sex again.

This is what I’m thinking as I’m cleaning the bathroom, picking clods of slimy hair out of the plug and squirting bleach into the toilet bowl.

How long had it been since my husband and I last did it? The Christmas decorations were still up, frost on the window. But now as I peer out, our front garden is a verdant green.

How could this have happened? Yes, life can be very unsexy, most of the time, I think, as I pull off my rubber gloves. But still.

I march outside to my husband’s office at the end of the garden where he’s still working even though it’s the weekend.

‘Do you want to have sex?’ I blurt out, standing there on the threshold, in my joggers and ratty old, only-wear-it-in-the-house jumper , not feeling very desirable.

‘No,’ he replies, not even turning around from his screen. And so I head back down the garden path – a little embarrassed, a little put out – and back inside, telling myself I wasn’t really in the mood anyway. But then when am I, these days?

My libido feels like it was stuffed back in the loft along with the Christmas decorations.

Panicked thoughts race through my mind. At 42 and after ten years of marriage and a total of 15 years together, are we growing apart? Does he not fancy me any more? Do I even fancy him still?

But yes, yes I do very much – he’s actually much hotter now than when we first met, aged 27. So what’s really going on? Am I just not a sexual person any more now I’m, whisper it, middle-aged?

Alice and her husband of ten years were having sex less and less frequently, and she feared if she didn't make the first move, it would never happen again

Before I let panic take complete hold, my desperate fingers type into ‘Dr Google’ asking if what I’m experiencing is ‘normal’. Turns out, this is so ‘normal’ it should be taught in sex education in schools.

My research brought me to the work of psychotherapist Esther Perel, whose book Mating In Captivity explained what I and – as it turns out – most people experience in a long-term relationship.

The closer you are to someone, paradoxically, the less desire you end up having for them over time, making eroticism and monogamy very unmatched bedfellows. Because here’s the thing: I’m no longer filled with an overwhelming urge to rip my husband’s clothes off the minute he walks through the door. The daily ‘what are we having for dinner, then?’ doesn’t exactly turn me on.

Casual sex with strangers feeds only on desire, which can actually make it easier. But my husband is also my best friend, admin assistant and the one who pushes the trolley alongside me in Sainsbury’s.

That intimate closeness we share, the very foundation our loving relationship is built on, is actually slowly eroding the erotic charge between us – a hostile environment in which to float an invitation to have sex into.

No wonder it’s got so hard to ask.

When we first met, my husband and I would hungrily kiss on dates, in bars, on the Tube, whenever we said hello or goodbye. When we moved in together we had sex in every room of our new flat (there were only three, alas) to christen it. Neither of us needed to initiate then, as sex was a foregone conclusion.

Yet as the years rolled by, the sex became less frequent, and nowadays we usually get down to it around once or twice a month. But what could I do about it? I decided I didn’t want that quest to my husband’s office at the end of the garden to remain fruitless – even if it didn’t result in hot sex on this occasion.

Because that’s the thing about asking for sex, you open yourself up to all outcomes. It makes you feel vulnerable, because no man – regardless of how it’s often portrayed on TV or in lads’ banter – says yes to sex all of the time. I probed what exactly was going through my mind when my husband told me ‘no’, he didn’t want to have sex with me. Well, there was the embarrassment – and shame. Because, I realise, society has shaped my thoughts so I sometimes believe it’s my role as a woman – as a wife – to be desirable, to mould myself around my husband’s wants.

Studies indicate that heterosexual men tend to initiate sex more than women do. But regardless of gender, if you’re the one who always decides, this can feel like a burden, as if you hold the responsibility for your shared sex life.

Historically, it was always pretty equal with me and my husband, but in recent years I’ve found myself being the one who asks more. Whenever he wants to, I usually say yes, seizing the rare opportunity with both hands. Because I love having sex when I have it.

Yet days, weeks, months can slip by and we’ve forgotten to have sex as neither of us has bothered to ask each other to have it.

But when did sex start to feel like just another thing to tick off the never-ending to-do list of everyday life?

Walk the dog, make breakfast, go to work, make dinner, make love. When did our erotic selves become so buried under everything else?

So, one Sunday afternoon, I set ou…