I went upstairs and sat down on my bed with the video camera, opened out the little viewing screen on its side and pressed play, then rewind. The screen came to life as the tape ran backwards showing the pool, the loungers, then Lucy in her lemon-yellow bikini. I let the tape run back for a few more seconds, then pressed play again. Daniel had filmed his sister as she sunbathed, going in for extreme close-ups of her belly button, the big toe of her right foot, and then a shot up her nose that zoomed in right up one nostril. The crash zoom was so fast it made me dizzy just watching it. Finally, she seemed to realise he was there, jumped up and began chasing him. The picture zig-zagged crazily as he ran away, his squeals of panic loud on the soundtrack.

It wasn’t very flattering but it did seem a bit of an over-reaction on Lucy’s part.

But still, all of it was going to have to be deleted. I just hoped there wasn’t too much – although he had been known to film in a kind of stream-of-consciousness style that went on for twenty, sometimes thirty minutes at a time. He often shot more footage than Sean.

I pressed stop and then rewind to take it back. The tape whirred as it spun backwards, the digital counter on the screen running down. I glanced out of the window. From our bedroom you could see out to the poolside, where Sean had sat Daniel down on a sunlounger and was talking to him at length, the boy nodding solemnly every so often.

It hadn’t always been like this. When we had first brought Daniel home from hospital, six-year-old Lucy had been absolutely ecstatic to have a sibling – a real baby of her own to go along with the assortment of toy babies she lined up in her bed every day for feeding, stories and bath time. But by the time he had learned to talk – and answer back – the sibling novelty had worn off and they had settled into a relationship that veered between grudging tolerance and open warfare on a daily basis. Daniel delighted in winding her up and Lucy delighted in taking offence – even more so now she was a teenager. It was an exhausting combination.

But I didn’t want them to grow up apart, to be separated, to have to be ferried from one parent to the other and back again every weekend, or whatever way custody arrangements worked. And however much they fought, they would want to be together too. They belonged together.

The camera gave a click as the tape reached the beginning. I pressed play and Daniel’s grinning face appeared as he introduced the house tour.