A book unread in my lap, the mid-afternoon heat prickling my skin with sweat, I kept one eye on my daughter and one on my son. Daniel was splashing in the shallow end of the pool with Odette, an assortment of inflatables floating around them. Rowan and Russ sat across from us on the opposite side of the pool, looking at their phones; the others had gone to explore the rock pools down in the gorge.

Sean and I were still barely speaking, but he was laid out on the lounger next to me – an uneasy truce for the sake of the children. I had been running through everything he had said when I confronted him twenty-four hours ago, feeling the ground still shifting beneath my feet.

I swear I’m not involved with Rowan.

It’s the truth.

He had denied it point-blank, without a flicker.

And maybe now I knew why – because it was the truth?

Not Rowan, but Jennifer.

Not for the first time, I kicked myself for not confronting him on Saturday when I’d discovered the messages on his phone. If I’d had the guts to do it right then and there, I could have got to the truth. Avoided this agony of suspicion and doubt. If I’d walked up to him and just showed him those messages straightaway, there would have been no way he could deny the affair.

The messages were proof. They were the key.

I’d wanted to unlock his phone again the following day, and the day after that, but he’d not left it out of his sight for more than a second – it was with him now, inches from his outstretched hand on the sunlounger. He lay flat on his back in the full glare of the sun, sunglasses on, skin glistening with factor 30. He burned every summer, with his pale Irish complexion, but it never seemed to put him off.

I’m a Leo, he would say with a grin. Us lions need to bask in the sun.

I turned my head slightly so that I could get a better look at him without attracting his attention. He was quite still, his broad chest rising and falling with a slow rhythm that I knew well from the thousands of nights we had shared a bed.

He was asleep.

And his mobile was right there within reach.

Russ and Rowan, across the pool, were still absorbed in their own phones.

Slowly, I shifted my weight, trying not to make a sound that might disturb him. Sitting up, I put my book on the floor and swung my legs off the lounger, leaning towards him so I could get a better look at his phone. It lay face-up on the edge of the lounger, not quite touching his hand.

I leaned in closer and pushed the power button. The phone’s lock screen appeared, asking for the unlock pattern.

Sean didn’t stir.