This is just perfect, sitting in a seaside drawing-room with the one you love, looking at old magazines and repeating last year's conversations word for word. This is what growing old will be like
The old man takes a painfully long time to come into the bar. I know because he was edging in through the main door as I went off to the loo and is just, finally, making it through the bar door as I return.

He must be over 80, thin, stooped, angular. His jaw is toothless, his nose beaky, his skin stained by years and weather. He wears a flat cloth cap, brown cord trousers, a check shirt, a pullover and jacket, though it's overwhelmingly hot and windless outside. He shuffles over to a wooden settle and the curly-haired waitress, who clearly knows him, brings him two bottles of ale.

"Mixing his beers," observes Jonathan wistfully. "That's an old-fashioned thing to do."

But this is an old-fashioned place, a politely sleepy, middle-class seaside town. There's a white lighthouse and a brewery and cream teas; quiet, cool shops with beige Burberry rainhats and Breton T-shirts in display cabinets; chemists full of elderly people actually buying those little violet cachou breath-freshener things.

We've been on the beach all morning, gobbling our paperbacks on the shingle while the children stand naked, screeching at the waves. Eventually, sick of sitting hunched on a towel, I went and hired the first deckchair of my life.

"Do you have an upright one?" I asked the man.

He foraged in the back of his hut and brought out a huge, worm-eaten, orange-striped seat with the majestic capacity of an armchair. We both regarded it in respectful silence.

"Try it out, if you like," he said soberly. So, equally soberly, I opened it and sat for a moment outside his hut as his tin kettle screamed to a boil. The floor of the hut was piled with old colour supplements and I wondered whether they, too, were for hire and what it was like to be the man and what he did in the winter when all the Londoners had gone and the beach huts were just a row of wooden shacks gazing at a cold grey sea.

He charged me pounds 2, explaining that I got pounds 1 back when I returned the chair.

After two hours on the beach, we dragged the children to this, our favourite bar, for lunch, brushed the sand off their legs, persuaded Chloe to put her knickers on, and fed them brown bread and butter and little bites of fish.

Then the old man came in. The ales leave a creamy crust on his upper lip. Jacob makes his hand into a spider and touches Chloe's leg and she screams her now legendary, heart-stopping scream. The couple sitting next to us laugh.

"I'm sorry," I say.

They smile, "Oh, please don't worry, we've got three of our own at home." They go on to tell us it's their wedding anniversary and they're having a night away.

"Then the last thing you want to do is sit next to our children," says Jonathan, moving gallantly between them and Raphael, who is trying to stand Batman and Robin up in the butter ramekin.

After half an hour or so, the old man leaves - just as slowly. We open the door for him and he doffs his cap. "Like Prince Charming," says Chloe.

Ten minutes later, there's a family trip to the lavatory and on the way back we pass Prince Charming again, asleep on a bench in the passage by the public phone. There are bubbles emerging from between his lips and as we pass, he shouts, "Bang! Bang!" and I'm the only one who jumps.

"Just a dream," sighs Jacob with benign, six-year-old tolerance.

That night, we get a babysitter and go to dinner at the posh hotel. First, we walk along the promenade. The sea is drowned in shadow, the beach almost deserted. Only teenagers lean against one another on the concrete by the padlocked huts. Cigarette smoke, low voices, laughter.

After dinner in the hushed, pink linen dining-room, coffee is brought in the even more hushed drawing-room. We sit on a sagging flowered sofa and Jonathan flicks through six-month-old copies of Country Life and Antiques Monthly. Suddenly incredibly happy, I kiss the side of his face. It smells of fresh air. "Don't start," he says, "People will think I've paid for you."

So, chastely, I pour the coffee from the heavy silver pot. The petit fours look and taste like Playdoh. "David Copperfield was filmed in this hotel," I remark. "There are photos of Susan Hampshire by the loo."

"I know," Jonathan smiles, "You told me last year."

This is just perfect, I think. This is the most you can ever hope for: sitting in a seaside drawing-room at night with the one you love, looking at very old magazines and repeating last year's conversations word for word. This is what growing old will be like.

And I hadn't noticed it, but now I do. There's a background noise in the room, a dull, droning monotone like a machine. Snoring. "We're practically the only ones awake," says Jonathan, "Look at them all." All around us, elderly people are blissfully asleep, mouths open, coffee cups in their laps.

We take one last look at the sea, now just a bottomless blackness and a muffled roar. Then we drive back through the country roads, which give up their moist late-August smells. B-movie pockets of mist swirl around the trees, and now and then our headlights pick up the panicked eyes of wild animals staring from the grass verge, twin discs of silver lit up for a moment and then gone.