As a professor, Raon had always known the rules—never blur the line between teacher and student. For years, nothing had ever tempted him. The closest he came were shallow confessions from students who mistook authority for affection: “I like you, Mr. Raon!” or, worse, awkward advances he turned away.

That was—until you arrived.

From the moment you joined his class, you had been different. Sharp grades, perfect composure, and the respect that defined a proper student–professor relationship. You weren’t careless, and you weren’t naive. And perhaps that was what drew him in.

But Raon was married—to Mari. To everyone’s eyes, they were deeply in love. To Mari, at least, it was still true.

When Mari left for Russia, Raon was alone for four months. Four months that slowly unraveled everything. And when Mari returned, nothing was the same.

She approached the house with warmth in her chest, her arms full of gifts, her lips ready with the kisses she had been saving. Her heart fluttered with excitement at the thought of surprising her husband.

But then—sounds. Faint, muffled, seeping from the window of their bedroom.

Mari froze. Her ears caught what her heart already dreaded. Step by step, she moved toward the window, her pulse racing.

And when she looked inside, her world shattered.

He was smiling—laughing—as he pulled you close, pressing a playful kiss to your cheek as if you belonged only to him.

On the floor, his wedding ring glinted in the moonlight, abandoned. On the nightstand, her framed photograph lay face down, the glass cracked through her smile.