This is a story about sex.

If you're still reading then better get comfortable - it could be a bit painful. Pull up a chair, pile up the cushions, fluff up your pillow and pull the blankets over your knees. Or if you're anything like me, recheck the lock on the W.C., take your shoes off and - here's the secret - take your socks off as well. Then check the lock on the door again. Settle down. Relax. Breathe in, then out. Ready? Good.

It begins in the middle. Of October, to be exact, right about the time I turn 30 and it occurs to me that I really ought to propose to my live-in girlfriend Shareel already. Ok, ok, so my mum puts me up to it, sneaks up on me one Saturday evening with a photo album under one arm and the news that she and dad were getting on in years and his latest check-up doesn't look too great and Shareel's pretty nice after all even if she isn't Chinese poor thing her parents are overseas and she's all alone here and she seems to like my cooking.

Of course I take the hint two hours ahead: I'm simply deciding how not to press the issue. She's come a long way from the time when she threatened to disown me and kick me out of the house for pre-marital fornication, miscegenation and general filial disobedience. I guess it helped that I moved out first. So instead, I offer her a coffee, thick with the Milkmaid condensed goo she still likes so much, while I retreat to behind my breakfast counter with my usual double latte. I'll do it, I tell her.

"So like I was saying, the doctor says your dad got high-blood pressure and diabetes and his eyesight also going a bit cloudy I hope it's not cataracts like your Aunt Linda, now that he's retired got nothing to do you know, he's lonely at home and I -"

I say I'll do it, mum.

"Do what, son?"

I'll ask Shareel if she wants to get married. Tonight.

She looks a little stunned, as if she's about to cry or cough up her last mouthful of caffeine, so I hurry on to add

No promises on anything else though. One thing at a time.

She nods slowly. The coffee cup is trembling ever so slightly in her hands. I pry it gently from her and steer her to a chair. She coughs once, twice and for just a moment as I hand her a sympathetic tissue, I catch an upward twitch of the lip I read as sly joy.

I suppose I should have waited until after our usual fun and games that night before popping the question. After all, she did seem as keen as ever right up until. I could smell it on her; I could taste in her kiss that she'd even brushed her teeth twice to make sure the Marlboro stink isn't as strong as usual. She puts her book down, lowers her pillow to dream position, is leaning on me with her eyes half-closed, her hand stroking down my jammies, searching for purchase. And then I go and open my big mouth.

I don't suppose we're going to have kids right after we get married?

Yes, I am a blubbering idiot.

"Who's getting married, dear?" she murmurs drowsily, prompting me like a fool to repeat myself.

We are, or at least, I hope we are. Soon. Get married I mean.

Her right hand stops two infuriating fingers away from my boxer shorts, the one with the Winnie-the-Pooh design from Pattaya. The lovely olive of one nipple, peeking through her satin nightgown, whisks away.

"And were you planning to ask me first, Mr. Home-maker-All-Of-A-Sudden?"

Why yes, after I've bought the ring and flowers, of course. And swore my undying love. I'd sweep her off her feet and drive down to the Housing Board to queue for a flat. I know the rules.

Shareel sits up, sighs and reaches for a cigarette. Never a good sign: not in the movies, not right now.

"I suppose we should talk about this properly," she says, pulling up the sheets. "It's your mum, isn't it?"

Yes, the usual. But I think she has a point this time, or rather, I think this time I agree with her. We've got our jobs, our car, our own place, and she's ok with us after all these years, so why not make her happy and keep her quiet once and for all? Nothing would change, except an extra tax break or two.

"Exactly, nothing would change. We already have everything we need. Did she talk about grandchildren?"

Shareel is truly beautiful when she sulks. The rich purse of her lip. Her flashing eyes, her floating hair. She swats one creeping hand away.

Not really, but it's hard not to get the hint. It's our call on that one, of course: we'll set the pace. If we're ready, when we're ready. And besides, what's wrong with two beautiful, fertile, financially secure young people wanting to have a baby together?

You know how we all sound like our parents when forcing ourselves to do something we don't really want to but feel we ought to? It's a bit like that: Self-discipline, courage, grinning and bearing it, taking the plunge: it all boils down to "eat your greens" and "don't touch" and "it's for your own good". Or maybe it's just me and mum, all those years of deprivation when she was too busy holding down a job while my father was getting his post-grad diploma, the endless waiting at the metal grilles of my grandmother's flat, staring down the corridor waiting for her to show for just one precious hour each night. And now I'm channelling her as compensation, I suppose. If I couldn't have her, be her.

Five pregnant seconds pass in silence. Ash flicks and smears the blue Friven 240-thread count sheets. The she hits me with it:

"We can't."

That floors me. I mean, I'm laying it on a bit thick and all, but this outright no is a bit of a rattle. But nothing compared to what comes next.

"I can't have kids with you." She stares at the gecko trying to make its way inconspicuously across the far bedroom wall. "Or with anyone."

Ok this is Major League stuff. This is All-Star Prime Time. This is CNN.

I brace myself with a pillow. She tells me about her complicated plumbing problem with unflinching candour. I'll spare you the gory details. Man, the stuff they tell you about your insides at the gynies - how in the world do folks get the idea that women are, of all things, delicate?

"And now that you know, I'm afraid I'm going have to kill you." She lights another roll and pulls a long drawl.

We can still get married, I say. All the more I should take care of you for the rest of your life.

"Don't be ridiculous," she interjects, smoke flaring from her beautiful upturned nose. "What's the point of getting married if you're not going to have children?"

It's pointless once she starts sounding like mum. The night is ruined. I flop back in defeat and retreat into a deep sleep with all the dreams wrung out of it.

We decide to keep mum to mum, of course, she would never understand, even though I tell myself it's not such a big deal. After all, 20% of all couples are infertile; that's like the entire graduate cohort if you extend that particular statistic to the general population. A fifth of all lovers, barren. Without issue. Childless. And that's probably only counting those who found out by trying, not those still in the dark or KO-ed by sudden revelations at midnight.

The worse part is the sex. Or lack of, thereof. My fault for the most part, I'm sorry to say. I had no idea up to that point how much of my go-to gung-ho get-it-on was tied to the notion, always at the back of the reptilian brain, that I was verbing it with a potentially impregnable partner, a biologically viable option. A maybe mother, no matter how remote the chances or how many barriers, biochemical, physical, karmic, whatever, came in between. It's sick, I know, and deeply sexist, misogynist, chauvinist and a couple of other -ists that haven't been invented yet. I know I'm not the one with the stigma, who has to live with the physical fact of infertility, the inconceivable tragedy of it. I plead guilty by way of wiring. Faced with a concrete wall my barrel could only fire blanks. No, not even blanks.

Pardon that last pun, it's completely unworthy of me, or of Shareel (who takes all of this with the most matter-of-fact surface calm, like a Catholic after confessional. Like a housing agent who signs off on the sale of a haunted apartment. Like a woman whose one devastating secret has been passed on like a baton on fire to someone who asked for it and now cannot refuse). You have to understand, the idea of Shareel, my lovely Shareel - the woman who first came up to me in college wanting to have her pictures taken in the nude, who gave me my first orgasm with another human being and my first all-night ethical discourse afterwards, who takes home a bigger pay cheque than any Philosophy major really deserves - never leaving a copy of herself behind for posterity? Why it nearly brings me to tears.

I'm talking about the woman I love here; the one who said in college, try everything once, that way you have the moral authority to turn it down; who has a taste for ancient positions with the oddest names, like The Passionate Narration, The Fish Exposes Its Gills, The Unicorn Shows Its Horn and The Silkworms Entwine; whose silhouette by moonlight is enough to get me cloud-drunk. She's painted ice-cream all over my navel with her tongue. Ice-cubes, hot wax. Some of the stuff I won't list is technically illegal here. This is one woman I'd do crazy things for. I think bitterly about the only words my grandmother ever said about Shareel, the first and last time she laid eyes on her before she died. "Big Hips, Many Babies."

You just don't expect the most natural fizz in the world to suddenly go, well, flat. But it just isn't easy to get going when you're feeling this blue, this futile about the future. It's in all the books. Look it up.

And it's not exactly a problem you talk over with guys at the office.

I try hot showers, tantric meditation, broadband internet porn. Nope, nope and nope. I read books smuggled from the SEX, HEALTH and SELF-EMPOWERMENT shelves of Borders. I frequent chatrooms:

Furtively, I brew up foul-smelling aphrodisiacs made from traditional herbs, spices and reptilian body parts. I stop short at "semen of virile young men mixed with the excrement of hawks or eagles and taken in pellet form", a favourite tonic, evidently, of ancient Chinese emperors. I fight down the nausea and bile, pregnant with disgust and growing desperation but trying keeping it all down where it nevertheless fails to do much good. The things we don't do for love. I try to be a man about being a man. In my balcony the potted Aloes and Hydrangeas wilt with neglect.

"It's so sweet of you," Shareel sighs after I top her off with a finger following another failed attempt to mount the battlements. "You could just leave me you know, find someone else."

I tell her not to be ridiculous, at the same time as I struggle back into my boxers, the ones with the strips and blue elephants, nothing has changed.

"Except knowing what you now know, which changes the future or your attitude to it. Everything's different," she says, slipping on her nightgown and heading for the bathroom, her long hair matted to the taut, glistening skin of her almost-too-long neck: a physical trait she will never pass down to her daughter.

I have no idea what to say to this. I'm not sure anyone does. So I do the next best thing - I point the finger at her.

You could have told me earlier, you know.

"Like when?"

Like when we first met, of course.

"Well, it's not exactly a conversation starter is it? ‘Hi my name is Shareel and I can't have children so might as well not tryE" The shower comes on at this point. She sounds as if she were in a cave behind a waterfall. "Besides, after we got together you kept saying you never wanted to have kids, couldn't bear the thought of -"

I know, I know, the thought of the overweening responsibility of bringing up a cluster of uncertain genes in a treacherous world and all that. I was an English major for pete's sake, cut me a little hyperbolic slack, so I tell Shareel.

But I must have meant it at the time. Or thought I did. All the way up until she told me we would never have the option of turning down children. I really don't like babies that much: squalling messy bundles of drool and excrement, scrunched up, wrinkled faces resembling nothing so much as a long-dead great-grandfather who grow up to be awkward, gangly, acned youngsters with more gripes than smarts. I've been there myself; I've shuddered at enough relative's brats, nearly dropped enough of them on their heads to know it was something I could never be quite good at. I think of parenthood the way others think of playing the piano, or football; some people just have the knack for it while the rest of us you could probably pick it up enough to get by if you really really have to, just to be a team player, just to please.

I wonder how much karma has to do with it; whether all those years of swearing off children, those frantic years crossing fingers about the odd burst rubber and missed pill, had really, after all, worked far too well.

"Seriously," she says, stepping out of the shower in a cloud of perfumed mist, "if you think it's such a big deal, why not just leave? Find someone else."

Trick question - or not? Does she WANT me to leave? Is she finally tired of a man who's lost his mojo because his woman has lost her topsoil?

"Of course not. But there's no use holding you back if it's going to come between us, now or later. That's why I don't think we should get married." She sits down next to me, naked, her skin an olive piece of heaven, firm and slightly moist. Still, nothing from the old soldier. Not the faintest salute.

The things we don't do for love.

Shareel, I declare finally, I would rather have no sex or babies with you than any other woman in the world.

It doesn't quite come out the right way, but she gets the idea, leans over and kisses me on the cheek, which I take as a yes.

"We'd better call your mum then."

Mum is overjoyed, overwrought, overwhelmed, and I'm glad we decide to do this before her heart is too worn out to take the strain. She comes over the next day, arms full of photo albums, bundles of letters and essence of chicken. She sits on the sofa, next to Shareel, clasps her hands tightly in her own small palms. And then it hits me that she's known about Shareel's condition for some time now. Something links these two women, something old and improbable and hard, glinting beneath the skin, the diamond of some unspoken understanding. And then they're both looking right at me.

"Son, there's something I've been wanting to tell you," mum says, in the ultra-calm, hyper-sane tone women use to talk about the long-deceased. And she does.

This is BBC News. This is Discovery channel.

Sex: it's the same old story, one we're all part of, one way or another. We all have to start somewhere, evidently not always how we imagine. However you write your personal history, it begins with a mother and father, egg and sperm, the alchemy of genetic material that makes you who you are. You trace your nose to one ancestor, your penchant for baldness to another. You take after your great-grandmother's laughter, your grandfather's absentmindedness, his wife's high-pitched voice and gift for numbers. An unreliable algorithm, to be sure, but nevertheless a system, a plan, a tree of cause and effect.

Well it's clearly not the whole story.

I admit to feeling just a bit faint after mum tells me too much of everything - the pregnancy that led to an early marriage, her miscarriage, the doctors telling her she could never have children, how she and dad came across this beautiful newborn in the orphanage they helped out in, the fight to push the adoption through, all the years of keeping it quiet so that their son would never know he was not their biological offspring, the love, the love.

Then of course we do what everyone does in the soaps: we bawl our hearts out in each other's arms. When it's all over I am left alone in the living room, motherless and fatherless, with the childless woman I love.

So that mid-October day when she finally decided to come and tell me the story, because by then she had found out about the lump in her breast - likely benign, says the doctors but you never know - she just wanted to come clean. She couldn't of course, after I spring the wedding thing on her, when she realised I didn't suspect a thing about her. Or about Shareel.

How long had she known? For a couple of months now, says Shareel: they've been having coffee together and talking, girl to girl.

Girl to Girl. Hard to think of your mum that way, as a woman with memories of youth and desire and pain. That quiet workaholic I call dad, with his unparalleled instinct for the steady and the good, no relation whatsoever, as it turns out, to my reeling, unbalanced self. No relation at all, except the thousand small joys stolen between deadlines. Their years of just getting by with me in it to complicate matters. The stories they've both told me of their childhood, on streets that no longer exist, climbing trees long since uprooted, sharing their histories and lives with a boy not even technically their own.

But of course their own. The same way this woman next to me now, whose every crevice and mood I know, whose deepest pain I may share but never fully plumb, is my own, my history. One love sets our yarn spinning, another keeps it going, so that in time we stumble our way to all the other strands. It's about sex and how little it matters and how much. It's how all our tales begin but it's not the whole story. All we do is start somewhere. The rest we make up as we go along.

This is Arts Central. This is Lifetime.

As it turns out we have enough savings to pay off the whole wedding ourselves and book a 5-roomer off the open market, and we don't even have to sell our car. It's just as well if we're planning to have a baby in the house. It's more like dating, not shopping; there's no formula or checklist, nothing but a second glance and the tiniest inner voice to tell you if you're on track. Or maybe the life of an adopted child is like any other's, put together one step at a time. One day you're this vulnerable, soft, living piece of clay, and before you know it, in just the right hands, you become tough as brick, solid as a wall in a safe house, just as impregnable, complete. I think of someone who will one day look nothing like either of us, but who will share Shareel's strength of spirit, her unsentimental common sense, my bad habits and odd tastes in jazz, our gaggle of relatives, our French food fetish, our interior decor and dying house plants. Someone who will probably know too much about our lives, more than we even realise.

I tell Shareel all this and she reckons it's my English major getting the better of me again. "That's not quite how I would put it," she says, kissing me. "But it's good enough for now." And I kiss her back.

If you ever get to read this you'd be too old to change anything, or Shareel and I will both be long out of the picture. At least that's what I'm hoping: this is really for me to work it out ahead of time, while I still remember it, a little of what I want you to know. It's just a start. The rest I'll have to tell you in person when we meet, somewhere in your past, my future.

I hope we'll feel it's all been worth it. I hope we get along. And I hope you like true stories, because what happens next, of course, is about sex, and about love, and about you.