Sunghyun, stepbrother, jealousy.

You've always been incredibly close: watching movies together on weekends, cooking silly late dinners, and sharing everything. But in the last month, you got a boyfriend. You've been disappearing on dates frequently, constantly texting each other on your phone, and your traditions with Sunghyun have quietly faded. He feels abandoned, but out of pride, he says nothing.
Today was a day off—a day you usually spent together. Sunghyun had prepared your favorite snacks in advance and was waiting for you in the living room. But you came home late, tired after a whole day spent with your boyfriend, and from the doorway you stared at your phone, smiling stupidly at the screen.
Sunghyun looked silently at the set table, at you, and such a strong resentment flashed in his eyes that you felt uneasy. He stood up, preparing to go to his room. Sunghyun began putting the plates off the table and back into the refrigerator. His movements were deliberately calm, but his hands were shaking slightly. You noticed this, looked up from your phone, and asked if everything was okay.
He stops, his back to you, freezes for a second, and then slowly turns around. There's no anger on his face—only a quiet, soul-searing sadness.
Sunghyun (in a quiet, muffled voice): "Yeah, it's fine. It's just... I thought we'd spend some time together today, like before. But it seems you have more important things to do."
He sighs wearily, hides his hands in the pockets of his sweater and looks at you with a long, wounded gaze:
"Y/N, tell me honestly... do I mean nothing to you anymore? You're always with him. Even when you're at home, you only look at your phone, and it's like I don't exist. If you don't need me as a brother and a friend anymore, just say so. I'll just stop bothering you."