Chapter Text
He should have known. He should have known someone like Katsuki wouldn’t actually love him.
He should have noticed that Katsuki never once told him he loved him. He never initiated anything, handholding, hugs, kisses, nothing. He should have noticed how he wanted to keep it a secret, from both their friends and family. And he should have noticed the way he looked at Kirishima.
He looked at Kirishima like he hung the moon. And the way he was with Kirishima. He hugged him, cuddled with him. He did things with Kirishima that he never did with Izuku. And then he started sleeping with Kirishima. He told Izuku that he had a night shift. Or was working late. And he came back with bruises. At first Izuku thought they were just from work. Getting hurt came with being a hero after all. That was until he saw the bitemarks. Kirishima’s bitemarks.
That was when Izuku began to notice things. 2 years after they got together, and 1 month after Izuku bought the ring he realized. Katsuki didn’t love him.
At first Izuku denied it as best he could. He told himself that he was just being paranoid. But there is only so much he can deny. So one day when he was offered the chance to go to America for 5 months he took it. He packed a backpack and suitcase and left.
Before he left he wrote Katsuki a note. He told Katsuki that he was leaving for America. And that he would be back. He told Katsuki that he didn’t have to wait for Izuku. Because Izuku was leaving him. Because Izuku knew about him and Kirishima.
4 hours later Izuku was on a plane to America. If his phone wasn’t turned off and he looked at it he would have seen the calls and texts from Katsuki. But he didn’t.
—
Katsuki got home late that night. As usual. These days after work he would go to Kirishima’s house. It used to be just so he could see his old friend. Then they started hooking up. And he started going almost every night.
Katsuki knew what he was doing was wrong. He had a boyfriend of 2 years after all. And he loved him. He did.
But Katsuki was self-destructive and just couldn’t get enough. The thrill of it. Or maybe it was his own form of revenge. Whatever it was, Katsuki didn’t stop.
Katsuki loved Kirishima, yes. But not like he loved Izuku. Izuku was the best thing that ever happened to Katsuki. He was too kind and just so beautiful. And he ruined it.
So when Katsuki got home to their apartment that day. And Izuku wasn’t home. He was scared. He was scared that Izuku had found out. And when he read the note Izuku left his fears were confirmed.
He knew it was his fault. He knew logically. But he hated it. And it made him sad. He tried calling Izuku first. Then he tried texting him. And then calling him again. And when none of that worked that sadness turned to anger. And the best way to release anger? Physical activity. Sex. So he stopped trying to call Izuku and called Kirishima. And asked him to come over.