But like all our other private jokes, this one seems to have curdled and hardened. Whether this is down to her actually starting to fancy Rich, or me just suspecting she might, I’ve no idea. He’s definitely a major-league shagger (Daphne once told me, ‘If Tinder was a computer game, Rich would have completed it,’ which I found both hilarious and slightly intimidating), but I don’t think there’s anything between them. The idea that there might be does hit me occasionally, like a punch in the gut. I guess I just can’t figure out why Daphne wouldn’t be interested in him. Or maybe she is interested in him, but she’s just not the kind of person who would do something about it.

I think suddenly about the messages from Alice, squirrelled away secretly on my phone. I’m exactly that kind of person, apparently.

When it comes down to it, I suppose that’s the reason Daphne’s still with me: because of the things she doesn’t know. She doesn’t know about Alice; she doesn’t know about Paris. She knows about Mum, obviously, but she doesn’t know the things I said to her before it happened. Things that still choke me awake in the middle of the night.

After fifteen years together, and four years of marriage, she doesn’t really know me at all. If she did, then surely she wouldn’t still be here.

She clicks open the front door, and makes to step out into the cold early-evening gloom. ‘I’d better go,’ she says, but she doesn’t. She just stands there, frowning at the doormat. ‘We can talk later. It’s just … Work is so draining at the moment, and then I come back here and it’s … even more draining, you know?’ She breaks off and fixes me with her big hazelnut-brown eyes, and she looks tired and really – genuinely – unhappy. And my insides freeze, because I’m suddenly sure she’s about to say something: something big and awful and final.

But then she glances through into the living room at the Christmas tree, and shakes her head, as if remembering that this is not traditionally the season for big, awful, final announcements.

‘Anyway, we can talk later,’ she says again. ‘And don’t worry about the thing tonight – I’ll think of something. Tell everyone you needed to put the decorations up, maybe.’ She looks again at the naked tree. ‘Actually, that wouldn’t technically be lying, would it?’

‘I’ll do it as soon as you’re gone, I promise. And the presents.’

She nods. Then she steps outside, shuts the door and she’s gone. And even though nothing was actually said, I can still feel the storm clouds gathering inside my head. We can talk later. She said that twice. But talk about what?