The secret of my Air Miles affair

I only have sex with my boyfriend once a month, yet he turns me on more than any man I've ever met. We have known each other for eight months and are very close - yet we couldn't be further apart. Yes, I'm in the midst of that most modern of relationships: an Air Miles affair.

Like the lovers in tonight's new Channel 4 series NY-LON, which chronicles such a romance, our paths crossed during a fleeting visit. As the editor of a travel guidebook, I had flown from my home town of London to Boston to meet potential contributors, and David's name had been suggested.

If someone had told me the large, bespectacled man in a knitted hat who shuffled into the bar would inspire me to write a steamy Valentine's Day poem just weeks later, I would have laughed in their face.

But, after a couple of drinks on expenses, we began to loosen up. He told me about the novel he was writing and the songs he composed for his indie band. He was fascinating, funny and sweet. "I think you're gorgeous," he blurted out, and I admired his un-British directness. I couldn't remember the last time I'd felt so comfortable with a man and I definitely wanted to see him again. There was just the small problem of a few thousand miles, a couple of time zones and a rather large body of water between us.

In a long-haul relationship, everything is accelerated. If the attraction is strong and you're only in town for a week, the natural impulse is to take a shortcut to the bedroom. Your sensible side protests that you hardly know this person and it will only end in tears. Your reckless side urges you to go for it - how can you get hurt when you live on different continents?

I held out for what seemed like a decent interval (two days) but, when sex with him rumbled off the erotic Richter scale, I immediately regretted the lost time. We spent the next four days in bed. A deep emotional attachment was forming. Was I in love, or was passion heightened by my return flight hanging over us like a Stealth bomber?

Back in London, I signed up for a cheap international phone package. The last time I'd spent this much time chatting to a guy, it was to a Peter Frampton soundtrack. David called every night at 6.30pm (11.30pm my time), the small window of opportunity after he finished work and before I went to bed. Paradoxically, our disembodied conversations intensified our emotional intimacy. We were forced just to talk. Through these chats, we got glimpses of each other's very different worlds.

I live alone in a sparsely furnished studio flat smack in the centre of the city; David shares an untidy house in the suburbs with the bass player in his band. He'd tell me about his gigs in grungy clubs and the underground arts events he covered for a local paper. I'd recount an outrageous drag cabaret I'd seen with my gay best friend, the latest exhibition at the Tate Modern or drinks with colleagues at a Primrose Hill gastropub.

Our emails became as fevered as exchanges in a cautionary 18th century epistolary novel - and a good deal more explicit. In one, David steamed up my computer screen with a virtual sex scene starring the two of us. After a couple of weeks I couldn't stand it. I booked a flight to Boston for Valentine's weekend.

It all felt vaguely familiar. I'm an American who has been resident in London for more than 15 years. I met my ex-husband while studying in the capital, but during the course of our romance I had to return to the US for 12 months to finish my degree. After a year of separation and enough love letters to stretch end to end across the Atlantic (this was the pre-internet age), I returned and we married. But this was different - Seb and I had been together a year before our relationship became long distance. My relationship with David was being built on snatched opportunities, across the 3,000-mile divide.

Over the next four months, I chalked up 25,000 Air Miles. In some ways, a long-distance lover is the perfect partner. With the demands of career, friends and other interests, an hour's phone conversation each night is about right, and monthly sex isn't too far off what most married couples manage. The danger is that fantasy can take over. I mentally liposuctioned David's substantial gut and, like women who forget the pain of childbirth, erased the memory of his jackhammer snoring until our next meeting. With the jet lag, it was a killer combination.

We were constantly starting over. It took a week to get used to each other, then I'd be flying home again. Culture clash kicked in when he came to London. In his own world he was clued-up and cool; here he seemed to morph into a crass Yank. I was mortified when an attendant at the Wallace Collection ticked him off for getting too close to a Gainsborough, and annoyed when he disrupted my orderly kitchen with a messy midnight snack.

Things weren't allowed to develop naturally, at a gradual, casual pace. When you're paying a week's salary on each Atlantic-spanning "date", you're constantly asking yourself: is this worth it? No, I decided. How could we make a commitment on the strength of what added up to a few weeks together? I wasn't about to uproot for a man - I'd already made that mistake once. I explained how I felt and he seemed to understand.

The troubl e was , after he left to go home, I was desolate. I started scanning fares on Ebookers.

Yet , wounded by my rejection, he cooled off considerably. His inaccessibility only made me more desperate. Fraught phone calls followed. "How can you just turn off your feelings?" I challenged him. "I care about you, but I don't want to be the thing that directs your life," was his sensible reply. But it didn't stop me feeling abandoned when the nightly phone calls trailed off. At one point, I didn't hear from him for two weeks and felt sure we'd broken up - but how can you break up with someone you're not actually with?

With the pressure off, the calls and emails slowly started up again, and I've decided to fly over for my birthday in October. I don't know if we have a future together, but there is no denying our bond. We enjoy each other's company too much to give it up, however ephemeral. Plus, I'm saving a fortune on cosmetics in duty free and I'm already halfway to a free Air Miles flight.