According to the National Sleep Foundation, 23% of which admit to sleeping in separate beds and 20% of all couples claim they have less sex and/or have lost interest in sex because they were too sleepy. The tension between Zoe and me was also common. "The resentments build up, then you explode," explained Dr. Rosalind Cartwright, Ph.D., director of the Rush University Sleep Center in Chicago, who further noted a high divorce rate among people with sleep problems. Then came the matter of my potential diagnosis.

The most likely was obstructive sleep apnea, a disorder where you intermittently stop breathing during the night. Recently, it has been linked to a host of disturbing problems from depression and diabetes to heart disease and stroke. The popular solution, a CPAP (Continuous Positive Airway Pressure) machine, is a Vader-like contraption that involves wearing a mask over your nose and/or mouth while you sleep.

My friend Peter said this of his newly prescribed CPAP machine: "If I was single, I’d be hiding that s**t in the closet." But, he added: "When I wake up in the morning now, I'm not 'hung over' from lack of sleep." Another friend, Chris, who had severe sleep apnea, tried the UPPP (uvulopalatopharyngoplasty) surgery, which involves removing soft tissue from the back of the throat, including all or part of the uvula, tonsils, and adenoids. "It just didn’t seem worth it," he concluded, after his snoring and apnea returned six months later. Paul, the younger brother of a college friend, also had the UPPP surgery, and it changed his life. He stopped snoring, no longer relied on caffeine to function, lost a significant amount of weight, and would "do it again in a heartbeat."

I arranged to take a sleep test. I didn't fancy the idea of connecting myself to a machine every night and the surgery seemed extreme, but I loved Zoe and it felt like our relationship was at stake. A few weeks later, I was sitting in a chair at a local hospital in my boxers and t-shirt while a stranger attached 28 electrodes to my head and legs. After seven fitful hours—a gauntlet more grueling than any single night with Zoe—I was awoken and told to go home. The results arrived two weeks later. Both Zoe and I had been playing it cool up until then, but we both knew it was a seminal moment. We’d already decided to hold off on shacking up—a move driven mostly by my fear of losing the precious few nights each week when I slept better alone. "What if I have to sleep with a machine—or have surgery?" I asked over breakfast the morning before I saw my doctor. "You're not going to have to do either," she smiled, then changed the subject.