As soon as we’re back inside, Dan locks the door. He asks Olivia if she’s okay and, after a mumbled ‘yeah’, he disappears up the stairs without saying a word to me.

Olivia slumps against the mirror but doesn’t resist when I put an arm around her and guide her into the living room. I leave her on the sofa, saying I’ll put the kettle on because that is, obviously, the solution to all of life’s problems.

When I return with two cups of tea, Olivia hasn’t moved. Her legs are curled under herself, her head resting on the back of the sofa. She’s staring aimlessly towards the corner of the room. The fact her phone isn’t in her hand is the biggest indication that she’s not happy. There are times where it might as well be surgically grafted to her.

‘Anything I can do, love?’ I ask.

She shakes her head.

I sit on the same sofa as Olivia and turn the television on, flicking through the channels until I find the repeat of a wildlife documentary. The volume is on low and there’s a herd of elephants sweeping across a barren landscape. I glance to Olivia and she’s twisted slightly to focus on the screen.

It’s as if we’ve gone back in time. When Olivia was younger, she’d come down the stairs in the morning and sit watching television in her pyjamas. Our strict food-at-the-table rule soon went out the window as we let her eat cereal on the sofa. In the evenings, we’d sometimes watch cookery shows together and wildlife documentaries. Then she found mobile phones and, probably worst of all, boys.

She changed – and so did I. No longer did she eat cereal on the sofa because she didn’t want breakfast. Watching a TV show when it was actually scheduled was so last century when she could stream her own clips off YouTube, or wherever.

It’s a long time with neither of us speaking – but we don’t need to. This is enough for me.

The peace is eventually broken by Dan bounding down the stairs and poking his head into the living room. He’s confused as he glances between us – but I can’t blame him for that. This is the longest Olivia and I have spent in the same room together in a fair while. Certainly, it’s the longest without arguing.

‘Everything okay?’ he asks.

‘We’re fine,’ I reply.

‘I’m meeting my personal trainer. We’re going for a 10k and then I’m heading into school. It’s parents’ evening tonight, so I’ll be late.’

‘Thank you for telling me.’

We can be forcibly polite when we want.

He hovers for a moment but then heads past with his backpack and briefcase. The door goes and then it’s quiet, except for David Attenborough’s soothing commentary.

‘How’s the Facebook page going?’ I ask.

Olivia shifts position, putting her feet on the floor and then angling herself in the opposite direction. ‘Okay.’

That’s hardly a ringing endorsement, so I don’t follow up, instead sitting quietly and enjoying the moment with my daughter.

It’s a few minutes later when Olivia breaks the silence. ‘Do you think he’s shagging her?’

She twists to look at me and, though I can feel her gaze, I can’t match it. Instinct tells me to scold her for her language but she’s eighteen, not eight.

As for the question… what is there to say? Disposition makes me think my husband probably is. I saw the way he looked at Alice and there was definitely something there that’s more than a trainer-client relationship. My head says no – what would Alice see in someone who’s more than twenty years older than her? My heart, the part of me that once cared, hopes he isn’t.

I can’t say any of that, of course, so I settle for replying that I don’t know.

‘Is that why you’re separating?’ Olivia asks.

‘No,’ I say. ‘We’ve been together a long time but we’ve grown apart. Some things don’t last forever.’

Olivia takes a breath and I know what she’s going to ask next. She isn’t stupid. ‘Did you stay together for me?’

‘I’m not sure this is really the thing to talk about, Liv.’

She reaches across and touches my knee, making me turn to her. ‘You can’t expect me to be an adult one minute and then treat me like a kid the next.’

My daughter speaks so calmly, so reasonably, that it melts me. Despite our problems and disagreements, those fights and days we’d avoid each other, it’s a moment like this that makes me believe we’ll be all right in the end. I love her so much.

‘True,’ I reply, slowly. It takes me a second to find the words, and then: ‘Honestly? We probably should have broken up ten years ago. Maybe longer.’

‘Why?’

I don’t know if this is an inappropriate subject but there’s no going back now.

‘I suppose we were never that well matched. I’d come off the back of a few things when I was a teenager and he was a slightly older man. It was only a few years but it’s enough at that age.’

I’ve somehow missed this fact in all the arguments with Olivia over Tyler. There’s a similar age gap with them as there is between Dan and I.

I gulp away the thought and then continue: ‘I was infatuated with him and I suppose he liked that I did much of the chasing after he first asked me out.’

‘What things had you come off the back of?’ I don’t reply straight away, so Olivia continues: ‘Ellie told me about how you, her and her brothers would spend time over at the watermill.’

There’s a second in which I’m temporarily stunned at the thought of Ellie spilling everything. The fact that my daughter might know more about me than I could ever be comfortable with.

‘We’d sit on the banks if it was nice, or shelter inside if it wasn’t,’ I say, keeping it simple. ‘Nobody bothered us. It was our little hideaway.’

When I speak of the mill, it feels more like a person than a place. It was a part of who we were as a group.

‘You told me it was out of bounds,’ Olivia replies. ‘You said it was too dangerous.’

I snigger at that. It’s hard not to. Parents make the best hypocrites. We tell our children not to lie and then spend however many years convincing them a bloke in a red suit comes down the chimney every Christmas.

‘I didn’t know you and Ellie talked about things like that,’ I reply.

‘We don’t… not always. I asked what you were like at my age.’

‘What did she say?’

‘Not much. Just that you’ve been friends a long time and that you were typical teenagers. You used to go out with her twin brother.’

I nod: ‘Wayne.’

‘I never knew that. I didn’t even know she had a twin.’

This is obviously the time to tell my daughter the thing I’ve kept from her throughout her life. There won’t be a better moment.

Except I can’t.

If I tell her about Wayne, then I have to tell her about Jason. And if I do that, then how can she ever respect me again? Why would she listen to what I have to say about anything?

‘I suppose I was in with the wrong crowd,’ I say.

‘Ellie was the wrong crowd?’

‘Not her. Just in general. I suppose that’s why I’ve been so concerned about you and Tyler. I don’t want you to repeat my mistakes.’

Olivia turns back to the screen, shifting her weight so that she’s angling away from me once more. I wonder if I’ve lost her. It was clumsy to bring things back to her but what else could I do other than evade her questions?

‘He’s not as bad as you think,’ she says quietly.

‘I only know what I’ve seen. If he’s better than that, then how is he better?’

Olivia doesn’t reply but there’s a big part of me that wouldn’t mind being wrong. I wish she could tell me how he makes her happy, how he enhances her life. It’s not as if I enjoy the arguing and fall-outs.

She doesn’t defend him, though. She takes her time, and I can hear her taking a series of deep breaths before she finally asks what’s been on her mind

‘Was I a mistake?’

‘No, Liv. Of course not.’

I shuffle across the sofa and hold her head onto my shoulder. She hugs me back, wrapping her arms around my chest and sitting with her legs across my lap.

‘Your father and I got married really quickly after starting to see each other. It was only a few months – but you were never a mistake. We wanted a child – both of us. You were the glue that bonded us together.’

‘But now you’re unstuck...’

I stroke her hair, searching for the words, trying to figure out how to tell her that the issues between Dan and me are ours alone.

‘There was a point where we realised we didn’t need each other. Your father had his life and his interests – and I had mine. The problem is that, by then, we had a house, a mortgage, car loans, credit card payments – and so on. A marriage is so much more than saying the words. We were living separate lives but unable to do it separately. You were at school, growing up, becoming a smart and independent young woman. It wouldn’t have been right to rip all that apart.’

Olivia doesn’t say anything but she presses her head harder into my shoulder. We both sit and watch the wildlife show, neither of us moving. The only sound is Attenborough’s calm, methodical voice seeping from the television. Thank God for Attenborough.

Eventually, Olivia disentangles herself. She’s upset and there’s dampness around her eyes which she wipes away.

‘That’s the opposite of selfish,’ she says unexpectedly.

‘What is?’

‘The other night, I said you were separating because it was what’s best for you. I thought you were being selfish – but you literally spent years making yourself unhappy so that I didn’t have to be.’

It takes me a couple of seconds to respond. It’s not what I expected to hear. ‘Not quite,’ I tell her. ‘Not really. Your father and I went through the motions over the years. We made a commitment when we decided to have you and, regardless of anything since, we stuck to that.’

Olivia’s eyes are ringed with tears once more. She tries to breathe but her nose is blocked, so she reaches to the table for a tissue.

Her smile is weary: ‘You’re going to be late for work.’