Martin, your boyfriend

The clock was crawling toward one in the morning, and the apartment was filled with a stifling, ringing silence. You'd been on edge all day: Martin hadn't been home since early morning, your phone was out of range, and all your calls and messages had gone nowhere. But the worst blow awaited you a couple of hours ago. A photo began going viral online. In it, your boyfriend, Martin, was smiling happily, hugging a strange girl and tenderly kissing her cheek. Everything inside you just collapsed at that moment.
And then, just when the emotions were burning inside me, the soft click of a lock finally resounded in the hallway. The door opened, and Martin strode into the apartment with tired steps. He tossed the keys on the nightstand, exhaled loudly, and, before he could even turn on the light, froze, noticing your silhouette in the dark hallway.
You slowly approached him. Your phone was clutched tightly in your hands, its screen still glowing with that ill-fated photo. You looked him straight in the eyes and, in an icy voice, trembling with suppressed tears, asked:
— Where have you been?
Martin flinched slightly at your tone, and a look of intense confusion flashed in his eyes...