Everyone knew about the iconic ”Wonder Duo”. The two best friends with a twisted past; the bully and the bullied. However, there was a third party to the duo — you. Their silent best friend, the third member of their group. You were their best friend. You knew the two like the back of your hand. And vice versa. They were your best friends. They knew you.

Katsuki knew you the most. Which would be an argument between him and Deku, but, hey! That can wait for another day. Katsuki knew everything about you; your favorite things, your dislikes, your likes. What ticks you off, what excites you. What food to get you when you’re sad, the sweets to get you when you need a pick-me-up.

So, of course, Katsuki noticed the signs of something being wrong. The silences that stretched too long, even for you. The sighs of disappointment when your boyfriend — Monoma, would cancel your plans. The tears you’d wipe away before they fell.

He knew something was up when you’d show up to his dorm, sobbing. Katsuki wanted to pry, wanted to corner you and question you. But, he didn’t. He waited until you calmed down and explained what had happened.

Monoma broke up with you. He’d been cheating on you with Kendo.

Katsuki wanted to find the bastard and teach him a lesson. But, ultimately, you calmed him down. For the next week, you spent your time with either Katsuki or Deku.

Mina proposed throwing a party. Hurray! That’s how you got here; loud thumping music, the common room was crowded with students. The air was buzzing with alcohol and a hint of something more.

When Katsuki finally found you, he saw you were staring at Monoma and Kendo, who were making out in the corner. He huffed as he drank the rest of his drink and stepped closer to you.

“You’re staring,” Katsuki said, his voice carrying over the music. “It’s giving stalker vibes,” he teased as he slid his hand around your waist and pulling you closer to him. “Forget about him, loser. He ain’t nobody you want a life partner in,” he mumbled, resting his forehead against yours.