The other night, I was roused from sleep, not by an amorous husband, but my six-year-old daughter weeing on me. It wasn't her fault - she was under the weather - more pertinently, I was in her bed again. Driven from the marital bed by my husband's snoring - and my own fitful insomnia - I frequently shack up in the spare room, and when that's taken, pad round the house, getting in with anyone who'll have me. (Guest numbers have dwindled).
For years, I kept my bed-hopping quiet, but then I started to hear stories - rumours circulating at dinner parties - were others at it too? If you're in a couple, I urge you step into my Circle of Trust: What did you do last night? And was your spouse there?
My name is Tash and I'm a kinky sleeper. Eight hours of straight snooze in the marital bed? Sorry, it doesn't do it for me; it hasn't since motherhood gifted me batlike hearing and the urge to wee like a sprinkler.
Now every evening follows a pattern.
7.30pm: I frogmarch our children to bed.
8.30pm: Supper cleared, I feel the first throb of anticipation.
8.45pm: It's here - the moment I've been lusting after since first I awoke. Elbowing my husband out of the way, I whip up a Horlicks and hotfoot it to bed.
I love my husband, but love my sleep more. And since we've married, I've just stopped getting it. When he's at home Mat stays up late, then sleeps like a log. I toss and turn, then rise with the lark (and generally swear at it). It's my husband who cops it worse though. If, by the following night, he's not in bed by 9.30pm, I'm hanging over the banister, yelling, "Goddamnit, man, it's not New Year's Eve!" When he does, finally, fall asleep beside me, I resent the fact I can't. Soon I fear it won't be just our nights fracturing. And I'm not the only one worried.
"We've unlearnt how to sleep," says Kathryn Pinkham, insomnia consultant and founder of The Insomnia Clinic (theinsomniaclinic.co.uk). We're working all hours, then texting as we brush our teeth, and, she points out, "losing the routine around bedtime". A third of us now manifest sleep problems - while our "other halves" take the hit. Insomniacs are four times more likely to develop mental health issues, and 60 per cent likelier to be obese.
Memory, concentration and motivation suffer, notes Pinkham, and "all this impacts on a relationship". Ironic, then, that insomnia often starts "when someone meets a partner with a different sleep schedule to their own". Honeymoon over, the couple's bed can become a battlefield.
My friend Karen (43) survived to tell the tale. As new lovers, she and her now-husband Jack used to spoon every night. For months, she says, "he tried to pretend we were as one" but Jack was a late-night kinda guy. While Karen slept in his arms, he lay rigid. And not in a good way. The admission came as a "total relief" - for both of them.
Now tired parents of two, they cherish their separate bedtimes. At 9pm, Karen heads up with a book to her "haven", leaving Jack to indulge his guilty passion in the lounge. ("He likes to do admin.") Hours after Karen's nodded off, Jack has grown adept at entering their room without a sound. "He's like a ninja," says Karen, touched by what her husband can do for her in his socks. Their children, however, are banned. "This is my space. I've never let the kids into the bedroom."
A hard line, perhaps, but a healthy one? For many couples, it's the coming of kids that signals the end of co-sleeping. One mate of mine ended up sleeping on the floor by her colicky baby's cot for months. Meanwhile her husband complained his nights were suffering "because he missed having me to cuddle". My hairdresser Tracy (35) ends up comforting her toddler twins so frequently, she's moved each into their own double bed.
(When sniffles strike, why pretend she won't be getting in with them?) Our own house can feel like Spaghetti Junction some nights - one kid rolling out of the top bunk, while another projectile vomits below. My husband, like most husbands, sleeps through the lot.
Bless the blokes - doing the sleeping, so we women don't have to! All blokes, that is, save for Nigel.
A dear family friend, Nigel is a 52-year-old accountant and practising insomniac. "I've been hooked on Night Nurse for 20 years," he confides. His bedside drawer is a graveyard for obsolete technology, testament to decades of missed zees and marital friction. When first married, he'd listen to "rainforest sounds" on his cassette player, only for his wife to rail against the scrape of turning tape and the escaping cry of bonobos. He subsequently invested in Mini-Discs, "but they whirred, she said". Updating to an iPod produced loud clicks and a lot of "Turn that f------ thing off", so Nigel turned in desperation to a sleep clinic. They sent him straight home again - loaded down with breathing apparatus. He subsequently passed a long, entirely sleepless night with tubes emerging from his ears, mouth and nose, while his wife vibrated furiously beside him. "It was," he conceded, "the lowest point." So why do it? Why keep sharing a bed? "We both find it hugely comforting," says Nigel. He may ruin his wife's rest, but she can't sleep without him.
It's a conjugal catch-22 for so many couples: We love the idea of cuddling up together, but hate each other by morning. So are we actually risking our relationship in our rush to conform to a romantic ideal? And whom exactly are we seeking to impress? Among all my married peers, I could find only one to admit to separate sleeping. "People's first response is suspicion," says Tabitha, a happily-married mother of four. Second response, however, is envy. " 'Oh my God', they say. 'If I had a spare bed, I'd be in it every night.' "
Exhausted by her husband's contrary sleep patterns, Tabitha moved into the spare room three years ago - and feels lucky to have had the option. "Most parents I know are bed-hopping at night - and we're all having issues with insomnia as we get older." She concedes her husband would rather still snuggle - "he feels lonely in the middle of the night" - but their sex-life hasn't suffered. "I just invite him up," says Tabitha. "Plus he's on a four-day week, which helps."
Flexible work hours can put the bounce back into any bedroom. (By 9pm, I am a stone, but catch me after elevenses and I'm rabid). So does sleeping together increase your odds of having sex? Not if your nights are disturbed, says Peter Saddington, Relate psychosexual counsellor and chair of the College of Sexual and Relationship Therapists. More and more couples are "just too stressed and tired" to... well, couple. We may still be going to bed together, but "the idea of the bedroom being a place of sex has gone out of the window".
Keen to batten down my husband's hatches - aware he's only got three nights at home before flying off to his next job - I call in the insomnia consultant. Pinkham prescribes "a sleep cleanse" to synch up - and crank up - our sleep drive: Mat and I are to stay downstairs together until 10.30pm (without drinking!) then head upstairs and put ourselves to sleep without aid of book, tech or television. Simple.
Except it's not, is it? First night back after a work trip, Mat wants to stay up late, and revel in being home. But I'm so shattered by the week, just saying "10.30pm" makes me want to cry. We part.
Night two: no cleansing occurs. ("It's Saturday night," says Mat. "There's no way I'm not having a beer.") The boiler's broken, so I go to bed early, hugging our youngest for warmth, then wake at 3am - for good.
Night three: we finally achieve cleansing. Mostly because we're both shattered, and Mat has to get up at 4am. So come 10.30pm, we retire to bed. And sleep. By 2am, I'm awake again, reading The Forsyte Saga in the spare room. Two hours later, I'm waving Mat off to the airport. Knock-out marital action? We'll try again next weekend.
• Some names have been changed