She is an unknown struggling writer. Her boyfriend is the new literary star. His book about American family life was the publishing sensation of last year. You'd think she'd be pleased for him. Think again. In a remarkably honest memoir, she describes what it's like to feel the one emotion more powerful than love...

THIS IS A STORY about two writers. A story, in other words, of envy. I met the man at an artists' colony, and I liked him from the first story I heard him tell. It was about how he'd once been jilted by a blind date, after which he went right out and bought himself some new clothes. He was working on his third book but had no particular interest in talking shop. He read the paper and watched sports on television. He was handsome in a shy, arrogant way, dressed safely but deliberately in his white shirts and black jeans.

He was, I soon learned, struggling.

There may be women out there who do not love this beyond all else in a man, but I'm not one of them.

He played pool after dinner and I would watch him through the window of the phone-booth door as I made my nightly call to my parents in California. My father, who was 81 and not in good health, had recently fallen. The anticipation of those 10-minute phone calls - during which I did nothing but listen, and even that not very well - dominated my days. The booth was tiny. The air felt pre-breathed and thick with the molecules of other people's long-distance calls, of their quarrels and appeasements. A small window was positioned at eye level if you were sitting down, and through it, while my parents' distress poured into my ear, I could see a slice of the man, a helping from his waist to the middle of his thighs, as he played pool. I watched him set his legs, wiggling them into place. As my mother spoke in the tense, coded voice that signalled that my father was in the room with her, I focused on the cue sliding forward and back across his body like a bow. As long as I kept my eye trained on that cue, I told myself, I would not get sucked through the tiny holes of the receiver.

One afternoon I ran into the man and, partly in a bid to keep him talking, told him about my parents and my uncertainty about what I should be doing to help them. His own father had died after a long illness, he told me, so he had some idea what I was going through. Just then a staff member came by and complimented him on one of his novels, neither of which I'd heard of - a fact that helped to equalise the discrepancy between his two published books and my none.

We both watched her walk away again, awkwardness rushing in to fill the space she left behind. He looked back at me. 'You have to do your work,' he said. 'That's your first responsibility.'

He meant, of course, my writing, and he spoke with a confidence I had never managed to feel about those hours of daydreaming at my desk, stringing together decorative little sentences to describe small, made-up events. Work to me always meant a job you were paid to do, necessary labour that someone else depended on.

He may have been struggling, but he knew what his work was. That was the first thing I envied about him.

WHEN MY FATHER, after at last agreeing to see the doctor, was immediately scheduled for major surgery, I made arrangements to fly back to California. I left my computer and most of my belongings behind to ensure my return to the colony, and I bought a copy of the man's second novel to take with me. Over the next week I read it in various locations - on the plane, in the hospital cafeteria, at my parents' breakfast table. There were moments, reading, where the recognition was so strong, and the life on the page so vivid, I could feel my pulse speed up.

This book is good, I thought with joy, the way you can when it's the work of someone you don't really know and expect you never will. Because it's the very fact of not knowing the writer that gives you that proprietary thrill, that frees up the book to belong to you.

But I did know him, at least a little, so I also felt, intermittently, the stabs of dread familiar to all writers - that here were sentences, paragraphs, whole pages I not only admired but wished I had written.

And I suppose pride was also in the mix because this man whose perception I envied had possibly liked me. I saw myself reflected, if in an incomplete and distorted way, in that possibility, the way you can see the ghost of yourself in a store window through which you can also see a real woman examining a shoe.

So from the start he was both man and writer, real and something more than real, to me. I had liked him as soon as I met him - a current rippled across my skin when he walked into a room - but something stronger kicked in once I met him on the page, naked and decked out in phrases I would never have thought of.

I was falling for another writer, and I recognised my descent by its peculiar calling card: the fear of what I wanted. Back at the colony, confident that nothing would actually 'happen' between us, I engineered as many coincidental meetings with him as I could. Because we lived on opposite sides of the country and would probably never see each other again, I felt crestfallen, and safe.

My father remained in the hospital, not so much recovering as trading one complication for another, for the next two months. Once I got home I visited him every day and never got over the feeling, as I searched for a parking space, walked to the entrance and made my way down the wide squeaky hallway to his open door, that I was pulling myself along like a reluctant dog who might one day slip my collar and make a break for the car.

Then one day in my mailbox there was a letter from the man at the colony. Of course I wrote him back right away, labouring for hours to strike an appro priately offhand tone. I drove my letter to the post office for faster pick-up and began waiting impatiently for a response. Before long we were corresponding, with a double-edged satisfaction that seemed destined to mark everything that happened between us. It was a simple thrill to see an envelope addressed in his hand in my mailbox, and then I would open the letter and begin answering it in my head, and the thrill would get complicated.

In my letters I was compelled to see my life as it must have looked from the outside: a lot of driving and errand-running, empty, necessary hours at the hos pital. His letters, chronicling his successes and failures at his desk, where he was at work on a novel about family troubles, reminded me of the writer's life I myself was failing to live.

I knew from his descriptions of his days that they were no easier than mine. He was still struggling, throwing away much of what he'd written, and I took a furtive solace in that. But occasionally he would report having had a good day, and I would feel, under my encouraging cheer, the shudder of panic you get when a friend deserts you by joining AA or leaving a bad marriage. It was one thing for him to be sitting down to it every day while I was not; but to hear that he might be getting somewhere made me feel abandoned and ashamed. Fortunately, over the next two months, such days were rare enough to discount.

Eventually my father came home to a house fitted for his wheelchair-bound return: doors taken off their hinges, rugs rolled up, and a hospital bed installed in the den, with a baby monitor so my mother could hear him call. But as he was ostensibly getting better, to the point where he was able to drag himself around the house behind a walker, he was also clearly getting worse. It was hard to get a firm sense of exactly what was wrong, and for a while I was frustrated because he seemed unwilling to make the necessary effort. Finally he agreed to go back to the hospital. As if his body had just been waiting for the signal, organ after organ began to shut down over the next few days. Even so, he fought to stay alive. He elected to go on a ventilator, after which he eventually slipped into unconsciousness. Two weeks later we finally decided to disconnect the machine that had been breathing for him. The doctor warned us that it might take him as long as a week to die. An hour later my father was gone.

I drove to the shopping centre that afternoon under cover of buying groceries and stopped to call the man from a payphone. I think he may have told me the story of the day his own father died, but I don't remember for certain. What I remember is just my relief that he was home, that when the phone rang, he answered. I remember standing outside a pizza parlour, watching the cars glide in and out of their spaces, listening to his voice.

The man seemed worried about me and surprised me by inviting me to come and visit him in New York. I still didn't know him well enough to feel comfortable with him, and I often felt nervous when I picked up the phone to call him. It was odd in one way and not odd at all in another to find myself sitting across the table from him in the apartment he had described to me in his letters. We talked for hours that first night, pushing the words back and forth while each of us tried to figure out what the other was saying underneath them. Finally I took my dishes to the sink and he came up behind me and, after all those months, put his hands on my shoulders.

OVER THE NEXT two years, as we visited each other for weeks and then months at a stretch, the man and I settled into a routine that included a lot of satisfying time together and a number of anguished fights. I looked forward to evening, to the sight of the man, who still felt new and mysterious, walking through the door, and I also dreaded that moment because it meant either lying about what I had accomplished or, worse, telling the truth. And it meant having to hear about his day.

Because the man, who had been struggling so agreeably when I met him, had finally found his key - the way in. In the months it took me to produce a drifty 15-page story about the end of a marriage, a short play about a woman who sleeps with her best friend's husband, and 70 pages of a screenplay that had the desperate signs of 'learning experience' written all over it, he piled up several hundred pages of his new novel.

It was, alas, good. My own reading told me this, but I had independent verification as well. As sections were finished they flew almost immediately into print, and just as immediately the phone would begin to ring with congratulatory messages, comparisons to dead writers and to living writers whose reputations were so established they might as well be dead. In the middle of this somewhat tense time the man came home one night, feeling frustrated after a couple of hard days and asked if I would read some pages that were giving him trouble. I was immensely relieved to think that he, too, could produce bad work, and grateful that he was willing to show it to me.

I had the sudden wish to knock him to the floor and hike up my skirt, but I thought I would read the pages first. He brought me olives and a glass of wine, and I sat down to read. Hoping for the worst and prepared to be encouraging.

'I don't understand,' I said when I finished. 'This is great.'

'Do you really think so?' he asked hopefully. 'You really think it's OK?'

'I think it's perfect. Funny, true, interesting.' I managed to shove the words up my throat and out of my mouth. I might have wished for it to be bad but I couldn't tell him it was if it wasn't.

'Thank you. That's a huge relief. That really helps. Thank you .'

You want to see bad work, I'll show you bad work, I thought, even as I was privately vowing never to show him another word I'd written.

I WAS 40, then 41, then 42 years old. I had no children. The husband I had thought I would be with for ever was gone, the father I always assumed would one day really know me was dead, and I had no career to speak of. And now I was with a man who could do this. The impulse to make love had passed.

When his novel was finally done, the man handed it in and his editor called every hundred pages or so to say he was loving it, then called to say he was cutting the cheque, and finally called to say he wanted to take the man and me out for a celebratory dinner.

Halfway through the meal, when the editor said something polite about wanting to read some of my work, I did not know what to say, and the man intervened: 'You did read it, actually. You passed on it.'

The editor, an urbane and gracious man, must have said something urbane and gracious then, but I couldn't hear him over the sound of my own voice in my head: Keep smiling, keep smiling!

Later that night, after the stony silence, the tears, the fury, I had to ask myself: What did I expect the man to do? I wanted it to be his fault, but it wasn't. I was angry about what he'd said but I would have been angry about whatever he'd said, even if he'd said nothing - because what I was really angry about was having to go out to dinner with an editor on whom my work had made so little impression he did not even remember reading it. An editor, it turned out, whom I liked , whom I thought was funny, sweet and smart, and who was going to do everything in his power to make sure the man I was with got the notice he deserved.

Over the next several months what had at first seemed like a pathologically extreme anticipation of the man's success on my part began to look like nothing more than a reasonable prediction. Advance copies of his book were released, and suddenly he was being interviewed, photographed, written and talked about by, it seemed, everyone. Clearly his book was on its way to becoming not a book but the book, and every day seemed to bring new evidence that he was on his way to becoming that rare thing, a writer people (not just other writers) had heard of.

On 11 September 2001 his book had been out about a week. I felt the sensation of disaster, the weird chill of fear and exhilaration at the possibility that the world and all its fixed routines might have changed in a single day.

As we tried along with everyone else to think about what had happened and what would happen next, another question went unasked: what would it mean for the man's book? I was sure he was wondering this, and I was too, but I let the day go by without mentioning it. In those strange hours when anything seemed possible, it seemed not all that unlikely that the book on which the man I loved had spent 10 years working might disappear before our eyes. And yet I said nothing.

I told myself it would be unseemly, even in the privacy of our apartment, to focus on our petty concerns when thousands of people had lost their lives and the fate of the world itself was suddenly uncertain. But the truth is I didn't mention his book because I didn't want to. Because for one day, at least, for the first time in what felt like months, he and his work had been eclipsed, and I was relieved.

That was the place envy had delivered me to.

MY FRIENDS, trying to be helpful, had this to say: 'I could never do that, be involved with a writer who was that much more successful than I was.'

But really: why not? Partly, I suppose, because a fellow writer's success makes it that much harder to console oneself with thoughts of what Virginia Woolf called 'the world's notorious indifference'. The world, Woolf said, 'does not ask people to write poems and novels and histories; it does not need them. It does not care whether Flaubert finds the right word or whether Carlyle scrupulously verifies this or that fact.' So when the man was merely gifted but not particularly rewarded I was comfortable; we were in it together, comrades in a world that didn't care what we had to tell it. But now, what did his success prove if not that when the gift is prodigious enough, the world does need us, it will pay?

When the subject of his success came up, often enough a friend would say, 'The great thing is he really deserves it.' Were they kidding? This was precisely what made it so hard. For once the gods hadn't made the stupid mistake of smiling on another no-talent, well-connected charlatan. No, this was a genuinely excellent piece of work by a man who had dedicated his life to doing such work and was now being rewarded for it: proof that the system was not essentially corrupt and misguided, incapable of recognising true merit, after all.

Where was the comfort in that?

I came home one evening and the man asked about my day, which had been unremarkable. I asked about his and learned that the British rights to his now-famous book had been sold for a whopping figure, higher than anyone had anticipated. It had been a big day, and he was proud and excited. It was the kind of news you want to call home with, and because his mother was no longer alive and he has no sisters, he had called his sister-in-law.

He hadn't known where to call me, he said, or he would have. But I could see it in his wary, eager face: he wanted to call someone whose enthusiasm he could trust. The part of me that was his girlfriend put her arms around him and told him how happy she was, and the other part, the miserable writer within, kept her distance.

Not long after this we broke up. At the end of a holiday trip to visit family in the west I told the man I couldn't imagine going back to New York; it was too hard there. I told him there wasn't enough air for both of us in that apartment; I told him I was drowning. He asked me to be more specific, and I told him I just didn't think I was cut out for this life together.

'What life? What are you talking about?' It was late; we were arguing in the dark, on a sofa bed in his brother's house.

'This life. Where you're so_ big, and I'm so little.' It made me feel littler just saying it.

'I don't think of you as little.'

The fact that I believed this helped not at all. I was drowning; what good did it do to hear that he thought I could swim?

But breaking up, it turned out, was not the answer, either. I still wanted him, and my pride, already inflamed, now fairly throbbed at the idea that it was my own weakness that kept me from having him. I was in pitched battle with myself, and the wrong side was winning.

A few months later, when I persuaded him to try again, I sensed this was our last good chance at being together. I also sensed, despite my recent conversion to the belief that problems are solved by talking, that this one, born of words, was one that words would never fix. The more I talked about it, the more secretive he would become and the more guilty and resentful we would both feel. It became, and remains, the thing we don't talk about.

When the man told me stories about his wife - his ex-wife, but she had a fearsome presence that made her more real to me than I sometimes felt to myself - I would feel a cool draught, as though someone had left the door to the future open a crack.

She had been a writer too. During the happy, lean years of their marriage they would both write eight hours a day, fuelled, in the starving-artist tradition, by a diet of rice and beans and jumbo packs of chicken thighs. They were going to publish together, the story went; their books would find their way to discerning, appreciative audiences. And when his first book made good on their bargain and hers did not, he tried to wait for her to catch up. She moved on to a second book and on to a second house, alone, where she hoped to work better without the distraction of his success. But the second book wouldn't come together; she couldn't finish it. It wasn't until they had finally separated, for good this time, that she gave herself the gift of putting that work away. As far as he knew, she had stopped writing altogether, except for an essay that had just been published in an anthology, which he learned about and bought one day.

In her essay, his ex-wife wrote about what it felt like when she and her husband separated. I had a hard time reading this; I was simultaneously so curious to know what she thought of their life together and so afraid to find out that the sentences kept shorting out on me. But I got the gist: she not only stopped writing when her marriage to the man dissolved; for a time, she stopped reading .

Well, I was in much better shape than that! On the other hand, he and I were still together. Who knew what I would have given up by the time it was over?

What would have happened, I wondered, if the situation had been reversed, and his wife had published first? He would have kept on, I'm sure; her success might have been satisfying or frustrating to him - perhaps both - but he would never have given up.

IT'S TEMPTING TO take comfort in generalisations, and I have. I see myself as belonging to a generation of women who were raised to believe that we could do and be whatever we wanted - by women who, by and large, had not enjoyed that freedom themselves (and who perhaps envied their daughters for it). I grew up still wanting all the old things - to be pretty, to be good, to be liked - and also wanting not to care about such things. But old habits die hard. Maybe it was no coincidence that when I was feeling most outstripped by the man's success and talent, when I was reading those pages of his that I wished I had written, I responded by withholding from him the gift of myself. When he was being lauded and invited, the world praising his intelligence and imagination, my way of evening the score was to shy away from him.

As long as he wanted and didn't quite have me , the logic went, we would be even, and I could stop feeling so outdone by what he had that I wanted. But what did that really mean? That if I could not be happy I was ready to make us both miserable. And that my answer to his work was my self ; he had his book to make the world love him, and I had my sex with which to take my revenge.

Life, obviously, is about more than this. It's not as though anyone thinks that being a good writer makes you a good person. But it helps. (Isn't this perhaps one reason why women, as a whole, are more apt than men to see writing and reading as therapeutic acts? All that private time spent rendering and transforming personal experience on paper is easier to justify if the writer - and, ideally, reader - is healed in the process.) If you're truly talented, then your work becomes your way of doing good in the world; if you're not, it's a self-indulgence, even an embarrassment.

But how do you know you're good if not by comparing yourself favourably to others (an essentially un-good activity)? And how many women are comfortable doing that? Here's Edith Wharton: 'If only my work were better, it would be all I need. But my kind of half-talent isn't much use as an escape.' Here's Joan Didion on the subject of her first novel: 'It's got a lot of sloppy stuff. Extraneous stuff. Words that don't work. Awkwardness. Scenes that should have been brought up, scenes that should have been played down. But then Play It As It Lays has a lot of sloppy stuff. I haven't re-read Common Prayer but I'm sure that does too.'

It's hard to talk about the category of 'women writers' or 'women's writing' without feeling that you're picking at a scab that will never heal as long as you keep picking. On the other hand, vexed as they are, those categories continue to be meaningful, even if we can't always agree on just what the meaning is.

Most women I know are reluctant to say, 'I am better than her, and her, and her - OK, I'll keep going.' And most men I know rely, when necessary, on some formulation of exactly that. Plus women have not only each other to compete against (in devious and exhausting ways, requiring much track-covering and nice-making as they go) but men to envy; because it's still the case that women writers are compared to each other, and the big (as opposed to, say, lyrical) literary novel persists as an essentially male category. Women's books are still not talked about in the same way men's books are, and women are still sensitive to that.

As I was turning all this over in my mind, I thought again about meeting my boyfriend for the first time. How before I had known anything about him, I had known this would happen - that one day he would write his Big Book, and the world would roll a red carpet to his door. All those months when he was miserably, triumphantly, cranking it out, page by artful page, I had known it, more certainly than I had ever known anything about my own life. (No wonder I had gotten so little of my own work done. I had been so preoccupied with monitoring his.)

Had I been clairvoyant, then? Or was it something more metaphysical: had my fear acted like a cosmic magnet, drawing to itself the object of its obsession (forgetting for a moment that my boyfriend might have had anything to do with his own fate)?

Or had I, in some perverse way, got exactly what I wanted? I had found a partner who, by being so good and so successful at what I wanted to do, had called my bluff. I didn't want to quit, it turned out. I wanted to find a way to keep writing, whether I could ever be good enough or not.

I did envy his talent - the way he could go off in the morning and come home at night with five smart pages, the way he could expertly tease out a metaphor, nail a character in a sentence, and tackle geopolitics or brain chemistry without breaking a sweat. I envied the fact that in airports and restaurants, strangers - readers! - would come up to him and rave about his book; I envied his easy acceptance at magazines that had been routinely rejecting my work for years.

For all that, though, I was startled to realise that I didn't wish I'd written his book, any more than I would have wished to wake up tomorrow looking like the beauty from a magazine cover. What I envied were what his talent and success had bestowed on him, a sense of the rightness of what he was doing. I wanted what women always want: permission. But he'd had that before this book was even written; it was, after all, the first thing I'd envied about him. It was arguably what enabled him to write the book in the first place.

I was raised to admire a life of service, and to this day I do admire it. When I see someone bend to the task of helping another I think she is doing the work of all, the human job. But someone else's good deed never stabs my heart the way a good book does. I admire it, but I do not envy it. Whatever else it has done, my envy of the man has helped me see the difference between what I was raised to want, what I wish I could want, and what I do want.

I FLATTER MYSELF that I'm doing better with it all, that I'm adjusting. The man and I are finally happy and at ease, for the most part, and his book and public stature are a fact of our life together.

But who am I kidding? At home sometimes I don't want to check the phone messages; when I step into a bookstore and see that stack on the new-book table, I can sometimes feel my heart rattling the bars of its cage. I read the reviews and the interviews, but not all of them; I want them to be good, and then I want to forget them. The book itself, which I've read twice, I don't even want to look at now.

That's how much better I'm doing.

And yet I am doing better because something within me has surfaced: another story. In this new story, every ugly impulse and selfish yearning, the whole insecure unlovable mess, has been given wing. There's no better self to protect any more; the moral high ground has been ceded.

In this story I don't do the work I was born to, perhaps not even the work I am best at, but the work I have chosen - incompletely, erratically, often unhappily and uncertainly. In this new story, I write to refute the ex-wife, and to avenge her. She is my enemy and my friend.

I have met the circumstances that are larger than my capacity to be gracious, it turns out. I have come up against the limits of my goodness: someone I love has what I want, and he probably always will. What else is there to do for it? I might as well work.

· The full version of this piece appears in the current issue of Granta magazine: Life's Like That, available in bookshops or direct from Granta for £9.99. Observer readers can subscribe to Granta for £24.95 for a year (37 per cent discount) and get Life's Like That free. Telephone FreeCall 0500 004 033 for details.