8 p.m. Just going round to Tom for a quick drink. Just for half an hour.

9st 2, alcohol units 4, cigarettes 3 (v.g.), calories 1326, Instants 0 (excellent), 1471 calls 12 (bad), hours spent asleep 15 (bad, but not self's fault as heatwave).

Managed to persuade Perpetua to let me stay at home to work. Certain she only agreed because she wants to sunbathe too. Mmmm. Got lovely new mini-break brochure: 'Pride of Britain: Leading Country House Hotels of the British Isles'. Marvellous. Going through all pages one by one imagining Daniel and me being alternately sexual and romantic in all the bedrooms and dining rooms.

11 a.m. Right: am going to, concentrate now.

11.25 a.m. Hmmm, got a bit of a scratchy nail.

11.35 a.m. God. I just started having paranoid fantasy for no reason about Daniel having an affair with someone else and thinking up dignified but cutting remarks to make him sorry. Now why should that be? Have I sensed with a woman's intuition that he is having an affair?

The trouble with trying to go out with people when you get older is that everything becomes so loaded. When you are partnerless in your thirties, the mild bore of not being in a relationship – no sex, not having anyone to hang out with on Sundays, going home from parties on your own all the time – gets infused with the paranoid notion that the reason you are not in a relationship is your age, you have had your last ever relationship and sexual experience ever, and it is all your fault for being too wild or wilful to settle down in the first bloom of youth.

You completely forget the fact that when you were twenty-two and you didn't have boyfriend or meet anyone you remotely fancied for twenty-three months you just thought it was a bit of a drag. The whole thing builds up out of all proportion, so finding a relationship seems a dazzling, almost insurmountable goal, and when you do start going out with someone it cannot possibly live up to expectations.

Is it that? Or is it that there is something wrong with me being with Daniel? Is Daniel having an affair?

11.50 a.m. Hmmm. Nail really is scratchy. Actually, if don't do something about it I'll start picking at it and next thing I'll have no fingernail left. Right, I'd better go and find an emery board. Come to think of it, this nail varnish generally is looking a bit scrotty. I really need to take it all off and start again. Might as well do it now while I think about it.

Noon. It is such a bloody bore when the weather is so hot and one's soi-disant boyfriend refuses to go anywhere nice with you. Feel he thinks I am trying to trap him into a mini-break; as if it were not a mini-break but marriage, three kids and cleaning out the toilet in house full of stripped pine in Stoke Newington. I think this is turning into a psychological crisis. I'm going to call Tom (can always do the catalogue stuff for Perpetua this evening).

12.30 p.m. Hmmm. Tom says if you go mini-breaking with somebody you are having a relationship with you spend the whole time worrying about how the relationship is going, so it is better just to go with a friend.

Apart from sex, I say. Apart from sex, he agrees. I'm going to meet Tom tonight with brochures to plan fantasy, or phantom mini-break. So I must work really hard this afternoon.

12.40 p.m. These shorts and T-shirt are too uncomfortable in this heat. I'm going to change into a long floaty dress.

Oh dear, my pants show through this dress now. I'd better put some flesh-coloured ones on in case someone comes to the door. Now, my Gossard Glossies ones would be perfect. I wonder where they are.

12.45 p.m. In fact think might put the Glossies– bra on to match if I can find it.

12.55 p.m. That's better.

1 p.m. Lunchtime! At last a bit of time off.

2 p.m. OK, so this afternoon I am really going to work and get everything done before the evening, then can go out. V. sleepy, though. It's so hot. Maybe I'll just close my eyes for five minutes. Catnaps are said to be an excellent way of reviving oneself. Used to excellent effect by Margaret Thatcher and Winston Churchill. Good idea. Maybe I'll lie down on the bed.

7.30 p.m. Oh, Bloody Hell.

9st 2, alcohol units 7, cigarettes 22, calories 2145, minutes spent inspecting face for wrinkles 230.

9 a.m. Hurrah! Night out with girls tonight.

7 p.m. Oh no. Turns out Rebecca is coming. An evening with Rebecca is like swimming in sea with jellyfish: all will be going along perfectly pleasantly then suddenly you get painful lashing, destroying confidence at stroke. Trouble is, Rebecca's stings are aimed so subtly at one's Achilles' heels, like Gulf War missiles going 'Fzzzzzz whoossssh' through Baghdad hotel corridors, that never see them coming. Sharon says am not twenty-four any more and should be mature enough to deal with Rebecca. She is right.

Midnight. Argor es wororrible. Am olanpassit. Face collapsin.

Ugh. Woke up this morning feeling happy (still drunk from last night), then suddenly remembered horror of how yesterday's girls' night had turned out. After first bottle of Chardonnay was just about to broach subject of constant mini-break frustration when Rebecca suddenly said, 'How's Magda?'

'Fine,' I replied.

'She's incredibly attractive, isn't she?'

'Mmm,' I said.

'And she's amazingly young-looking – I mean she could easily pass for twenty-four or twenty-five. You were at school together, weren't you, Bridget? Was she three or four years below you?'

'She's six months older,' I said, feeling the first twinges of horror.

'Really?' said Rebecca, then left a long, embarrassed pause. 'Well, Magda's lucky. She's got really good skin.'

I felt the blood draining from my brain as the horrible truth of what Rebecca was saying hit me.

'I mean, she doesn't smile as much as you do. That's probably why she hasn't got so many lines.'

I grasped the table for support, trying to get my breath. I am ageing prematurely, I realized. Like a time-release film of a plum turning into a prune.

'How's your diet going, Rebecca?, said Shazzer.

Aargh. Instead of denying it, Jude and Shazzer were accepting my premature ageing as read, tactfully trying to change the subject to spare my feelings. I sat, in a spiral of terror, grasping my sagging face.

'Just going to the ladies,' I said through clenched teeth like a ventriloquist keeping my face fixed, to reduce the appearance of wrinkles.

'Are you all right, Bridge?' said rude.

'Fn,' I replied stiffly.

Once in front of the mirror I reeled as the harsh overhead lighting revealed my thick, age-hardened, sagging flesh. I imagined the others back at the table, chiding Rebecca for alerting me to what everyone had long been saying about me but I never needed to know.