But the sense of closeness was short-lived. After supper, the three of them trooped through to the sitting room to watch a re-run of an old Inspector Morse mystery. Roz sat down first on the two-seater sofa, and Tamsin – immediately, deliberately, Callum thought – sat down next to her, leaving the three-seater for him to sit on.

‘Oh no, you two have this one, much cosier,’ said Roz, starting to get up.

Tamsin put a hand on her mother’s knee and pushed her down again. ‘It’s fine, we’re fine, we can manage an hour or two apart,’ she said testily.

Tamsin took in very little of the Morse: instead, she spent the next two hours deep in contemplation, staring at the screen with unfocused gaze. Mostly she was day-dreaming about Chris, as she had been since the weekend. She wanted him and he wanted her: that much she knew now, for certain. And she was very glad indeed to have walked away from the situation on Saturday. To think that she had so nearly stooped to her father’s level! But she hadn’t: that was the whole point. She had been tried, and she had not been found wanting. Before anything happened between her and Chris she was going to break up with Callum. When, though? Obviously things couldn’t go on like this for much longer. She was being unfair to him, she could see that. But he had those scholarships coming up, and then that trip to France: whatever she might think of his spoilt little pupils, she knew how much he cared about the job, and she didn’t want to make things unnecessarily difficult for him.

‘When’s your Easter holiday start?’ she asked during one of the ad breaks.

‘End of March,’ said Callum. ‘Why, do you want to go away somewhere?’

‘No, I was just wondering.’

So that was it, she promised herself. It was going to be horrible but she would do it, without fail, at the beginning of his holiday: that way he’d have a good three weeks to sort himself out before term started up again. It was surely the kindest way. And then there would be almost five months before Chris came back – a decent interval.

It felt like a reality now, in a way it hadn’t before. She was really going to sit him down and tell him she didn’t want to be with him any more. The thought of this conversation – how painful it would be for both of them, but especially for Callum – aroused a strong, almost indignant protectiveness in Tamsin – as if the threat posed to Callum’s happiness came from someone other than herself. At the end of the programme she padded over to his sofa and sat down on his lap.

‘You are staying over, aren’t you?’ she asked, kissing him gently on the cheek.