‘You don’t mean that.’ She frowns, although her forehead doesn’t move as much as a fifty-two-year-old woman’s should.

I think about it. She’s right that I should probably have questions, or feel angry, or sad, or betrayed. After all, as she pointed out, I’ve always been so adamant that I’d never let anyone cheat on me after my dad did the dirty on my mum when I was a teenager. But the truth is I can’t bring myself to care very much. Neither am I very surprised. Darren is hot – at least, his body is, because he spends most of his time either at the gym or training for some triathlon or other. The trouble is, most of the time it’s the only topic of conversation he has, and I’ve found myself drifting off on more than one occasion when he’s bored me half to sleep with tales of PBs and split-runs and fartleks.

‘I really think I do mean it,’ I say to Kirstie. I tug on her arm. ‘Come on, let’s run.’ And before she can say anything else, I sprint off, leaving her to catch me up.

* * *

The training session is brutal, as is usual with Kirstie. And while I find Darren’s obsession with fitness an ick, with Kirstie it’s just who she is. Crazy running schedules, ultra-marathons, extreme sports, throwing herself off cliffs – ever since the kids left home she’s taken it to even more extremes. She even left her job with a PR firm four years ago to set up as a personal trainer – which of course has taken off in a huge way, with loads of very rich men and women spending several hours a week training with her for extortionate fees. I’m proud of her. Not many people could have made it work the way she has. She’s a machine.

‘I was going to go home for an ice bath, but I think you need a strong drink,’ Kirstie says, as she pushes my foot closer to my bum and I feel the roar of a sore quadricep as the stretch deepens.

‘Ow!’ I relax a little. ‘I need to eat first, I’m starving.’

Kirstie hooks her foot onto a nearby bollard, leans forward into a hamstring stretch, and nods. ‘Fine. La Cocina in half an hour?’

‘Deal.’

So much for my lazy night in, I think, as I step out of the shower and pull on my favourite skinny jeans twenty minutes later. I love Kirstie but she’s like a Duracell bunny, never running out of energy – whereas after the day I’ve had, followed by that punishing hilly run, I’m not sure I have the energy left to even walk to our favourite tapas restaurant. I consider cycling, but then remember there’s nowhere to lock my bike up, so pull on flat shoes and set off at a brisk walk.

Kirstie is already there when I arrive – of course she is – and I sink into the seat opposite her and pour a glass of water. When I put the glass down and wipe my mouth she’s staring at me. She would have a creased forehead if it wasn’t pumped full of Botox, but the expression on her face is still clear.

‘What?’ I say, picking up the wine menu.

She folds her arms across her chest. ‘You don’t seem very upset.’

I put the menu down. ‘About Darren?’

‘Of course about Darren.’

I twirl my empty wine glass and watch it spin. ‘I’m not.’ She continues to study me and I finally look up and meet her eye. ‘Honestly, Kirst. I’m not that surprised.’

‘And you’re not upset?’

I shake my head. ‘Not really. I mean, it was only ever casual. Besides, you know what I say – once a cheat, always a cheat. I’m probably better off without him.’

‘I know but it has been six months. I thought you might like him more than you were letting on.’

I shrug. ‘You know what, I really don’t think I do. He was nice to look at and have around, but I never saw us going anywhere.’

She finally smiles, her white teeth gleaming in the candlelight. ‘Well, good. I was really worried about telling you.’

I feel a smile creep across my face too. ‘I’m glad you did. But I could never take any man seriously when he spends so much time in Lycra.’

Kirstie lets out a bark of laughter. The people on the table next to us glance over and she reduces it to a low chuckle. I love her laugh. It’s loud and ridiculous but totally genuine and so infectious it always makes me laugh too.

‘So, what are you going to do?’

‘Tell him it’s over, I guess.’

She grins. ‘You could always cut up all his clothes.’

‘Or slash his bike tyres.’

‘Hide his running trainers.’

‘Put itching powder inside his underpants.’

Kirstie laughs again, almost spitting water across the table. ‘Itching powder? What is this, nineteen-eighty-three?’