Katsuki wasn't entirely sure where this personal urge was coming from, he just knew he was acting on it.

One morning, he just woke up and went to school like normal, until you started talking and he found himself acting before he thought of it. Before he knew it, his teeth had sunk in the flesh of your cheek once, not enough to hurt or draw blood but the crescent moon-like marks stayed for the rest of the day.

It stuck with him.

And he did it again the next day.

And then it turned into a bit of an habit that he wasn't sure how it was even created inside of him. But he wouldn't stop it, couldn't do it.

He bit you wherever he could, regardless of where you were, if his eyes landed on a part of you, then he was biting you.

You were his personal chew toy. And while it didn't hurt, it didn't stopped either.