The game of water polo carried on regardless, Sean, Lucy and Rowan versus Alistair and his boys. Sean and Alistair manned the goals at each end of the pool, while Rowan and the three teenagers blocked and dodged and took shots in the space in between. Sean was distracted, his eyes still wandering towards me, but I refused to give him the eye contact he was looking for. My eyes were firmly on Lucy, her golden hair fanned out behind her in the water, swimming and diving and turning like a beautiful mermaid. My little girl. Jake and Ethan had left their phones on a side table and they were pinging and bleeping almost constantly with notifications, a continuous stream of updates on social media that seemed ferociously frequent even by teenage standards. But it was nice to see Lucy – to see all three teenagers – doing something that didn’t involve their mobiles, that didn’t involve the endless picture-posting and status-sharing, the comparison with friends and the unspoken fear of missing out that drove the constant need to be connected all day, every day.

*

It was subtle, at first.

So subtle I almost didn’t register it.

But as the ball was thrown back and forth and the players splashed and laughed, a sense of unease began creeping up my arms. With every goal scored, every shot blocked, the distance between certain players in the middle – Lucy, Jake and Ethan, to be precise – got smaller. And then a little smaller still, until only a few feet separated them. The brothers moved further and further into the deep end, into Lucy’s half of the pool.

As I watched, the prickle of concern climbing up to the back of my neck, Lucy got the ball and raised it high to throw at the goal. Ethan waded towards her and hurled himself forward with his arms raised high to take the ball from her, lunging into her, pushing his body into hers, no space between them at all, faces inches apart, arms touching, hands touching, his chest against hers, skin to skin, nose to nose, him pushing and reaching and grabbing in a full-contact tackle, his shoulders and arms overpowering her slender frame, his hands snatching the ball away from her and holding it up, and I knew, I just knew, that what he wanted more than anything was for her to come back at him and try to take it away as he had just done.

Instead, Jake lunged at his brother and took the ball from him, hurling it aside and shoving his brother in the chest. Pushing him away from Lucy.

‘What the hell, Ethan?’ he shouted angrily. ‘It’s not a bloody rugby line-out, all right? It’s not supposed to be full contact.’

‘Chill out, bro.’ Ethan splashed water into his brother’s face. ‘Just a game, isn’t it?’