I knew, of course, what I should have done. I should have marched down to the pool and asked him about the messages, what they meant, who they were from. Who she was.

But I didn’t.

As the shower water pounded the back of my neck, it started to feel that it wasn’t enough, in the scales of our relationship: one flippant question weighed against twenty years together. There wasn’t enough weight to it, enough heft, to justify hurling this slender missile at him. It almost didn’t seem fair to justify wrecking what we had. It would have been . . . irresponsible, somehow. Our marriage wasn’t perfect by any means, but who has a perfect marriage? I was happy enough, and I thought he was too. Maybe if I could find out more, I could fix it, rather than destroying it with one reckless question.

And of course I was scared, too. Scared that he would leave me and the kids, discard us for something new. I didn’t want it to be real. Didn’t want to make it real, any more than it already was. I was scared that saying it out loud would make it real.

So I didn’t. I couldn’t. How do you even start that conversation?

So, Sean, I memorised the unlock code for your phone and waited for you to leave it unguarded. So who’s the other woman? Who is she? What the hell is going on?

How could you do this to me? To our family?

I rehearsed it in my head, practised forming the words in my mouth. Imagined hearing myself saying them. But it all sounded crazy, even to me. So I didn’t say any of those things. I stood in the shower and let the water mingle with my tears.

I remembered Googling it a few weeks ago – like a typical twenty-first-century hypochondriac trying to decide between a headache and a brain tumour – and discovered that infidelity happened in about a third of committed relationships. Which meant that, statistically, one of us on this holiday would fall victim.

Was already a victim.

There was another option, of course: to pretend I never saw the messages. Pretend I had never looked. Just let myself float along with the current, as if everything was still the way it was. Why rock the boat? Maybe it would be better to just imagine he was the good husband and I was the good wife who didn’t snoop on his phone. Didn’t see what could not now be unseen. But I hated the not-knowing, the grey area between the truth and everything else. Black and white suited me best; I didn’t deal well with grey. Never had. I wanted to know – for sure – one way or the other, before deciding what to do next.