Eleven years into our relationship, I am finally prepared to admit that my partner and I have stopped sleeping together. It's not a case of the first throes of passion between a couple who met in their mid-50s sliding gently into a more companionate phase. Nor is it a matter of him moving into the spare room because one of us snores.
No, what I mean by stopping sleeping together is perhaps best expressed by turning the sentence around. Together, we stopped sleeping.
Far from our sleep problems uniting us in mutual compassion and empathy, we have entered into what I call the competitive sleep phase of our relationship. It is characterised not by boasting about how well we've slept, or sharing lurid dreams - rather by how badly we've fared in the night. When his alarm goes off at 6.20am, I ask groggily: "How was it for you?"
"Awful," he generally replies, "awake more than two hours in the middle of the night. And you?"
"Ha!" I gloat. "Thought I heard you tossing and turning. But I was awake for three hours myself..."
The winner in this bizarre competition that has come to dominate our nights together is the one who has suffered the most by virtue of sleeping the least.
I've tried being mindful, I've tried acupuncture and various tinctures and tonics. I've listened to soothing sounds, waves swishing against seashores, babbling brooks, courtesy of countless apps.
I've even turned the white light of my Kindle so low, I'm practically reading in the dark, which I'm sure is ruining my already deteriorating eyesight.
And while I've been genning up on this admittedly fascinating subject with the help of renowned neuroscientist and sleep expert Matthew Walker's Why We Sleep: The New Science of Sleep and Dreams (Allen Lane), the more worried I become. And the less able to sleep.
In the interests of a sharing relationship, I keep quoting bits at my partner, adding to his paranoia. Like the not-so-jolly news that if you routinely sleep less than six or seven hours a night, it will demolish your immune system, double your risk of cancer, increase your risk of Alzheimer's disease, diabetes, stroke and heart failure - exactly the sort of stuff we end up mulling over in the middle of the night.
Through our waking nightmare, at least my partner and I have retained a modicum of humour. As we lay to rest last night, my partner kissed me.
"Good night, darling," he said, before adding: "Only kidding."