I downloaded the app because of a joke.

Marcus had been teasing me for weeks that I snored like a chainsaw, and I refused to believe him. So I found one of those sleep-monitoring apps, the kind that listens through the night and only starts recording when it picks up a sound. I set the phone face-down on the nightstand, plugged it in, and fell asleep certain I'd wake up vindicated. Quiet as a mouse, I told myself. He'll see.

The next morning I opened the app expecting maybe two or three little clips. Instead there was a long column of them, dozens, neatly time-stamped in the small hours. 3:51. 4:02. 4:09. I almost laughed. Apparently I was worse than he'd claimed.

I tapped the first one to hear the damage.

It wasn't snoring. It wasn't even sleep-breathing. It was a soft electronic click, the unmistakable sound of a phone being woken, and then a voice. My voice. Younger, lighter, laughing at something off in the distance of a memory I hadn't visited in years. It took me a full ten seconds to understand what I was listening to, and when I did, the warmth drained out of the room.

They were my old voice memos. Private ones, from a relationship that had ended long before Marcus. Things I'd recorded for an ex and never deleted, buried four folders deep, behind a passcode. And here they were, playing aloud in my dark bedroom at four in the morning while I slept three feet away.

I scrolled, my thumb cold. Clip after clip. The pattern was always the same. The click of the screen. A pause while he typed my passcode, the one I'd never given him. Then my own past, my own intimacies, played quietly into the still air like he was studying them. Once, between recordings, I heard him exhale slowly, the long breath of a man searching for something he was terrified to find.

He'd done it the whole night. Sat on the edge of the bed I shared with him, holding my phone in his hands, listening to who I used to love.

When he came back from his run, glowing and ordinary, I set the phone on the kitchen table and pressed play. I watched his face go from confusion to recognition to a grey, sick stillness. He didn't ask how I'd caught him. He didn't even pretend it was a misunderstanding. He just said, in a flat small voice, that he'd been sure I was hiding something, that he'd needed to know, that he'd been afraid for months.

What he never understood was the irony I couldn't stop turning over in my head. He'd torn through my past hunting for a betrayal that wasn't there, and in doing so he'd left the only one that mattered recorded in perfect, time-stamped detail.

The app had been listening for a chainsaw. It caught a thief instead.

I packed a bag that afternoon. He kept saying he could explain. The recordings already had.