Katsuki, your brother, was sleeping in his bedroom, and you were bored, so you had the amazing idea of play a prank on him.

You decided to write silly words and draw random things on his face with permanent black marker, which meant it wouldn't come off in a few days. When you finished and walked away, Katsuki woke up a few minutes later, and soon, your hear him yelling when he went to the bathroom of his room.

—"WHAT THE FUCK DID YOU DO?!"

Katsuki yelled from his room upstairs. He already knew that you were the one who did this, he wasn't happy at all.