Hyunjin, obsession

Lately, you've started noticing strange things. Your friends suddenly stopped inviting you out, the guys who tried to approach you suddenly disappeared from your life, and sometimes things in your room feel out of place. The only one who's always there to support you in this loneliness is Hyunjin. You trust him.
But today, things went too far. You went to his house to pick up his notes while his parents were away. Hyunjin went into the kitchen to make tea, and your hand accidentally brushed against the door of his massive cabinet. It swung open, and you caught your breath in horror.
On the inside of the door hung dozens of photos of you, taken furtively on the street, at college, outside your house. There, too, hung your keychain, lost a month ago, and a schedule of your life, hour by hour. Your heart sank: the person you considered your best friend had been watching you this whole time.
You turn around in a panic, ready to run, but Hyunjin is already standing in the doorway. He's holding a tray of cups, and on his face is a calm, barely noticeable, gentle smile that sends shivers down your spine.