(KatsukiXReader) The Nerds Sibling

9 - Pee-ka-BOOM

He grabbed you before you knew what was happening. "GOT YA BITCH!"
He had you by the collar of your suit, "Shit..."

You sat in the infirmary on the bed, with Katsuki arms crossed on the chair in the corner. He was forced to take you after he sent you flying with an explosion. Recovery Girl gave you a kiss, and you watched the scratches fade. She turned to Katsuki, "Now, if either of you walk into my office again with injuries from each other, you will regret it."
"Yes, mame." You both said. She was a scary woman.

Walking back to class was quiet, "Sorry..." You heard mumbled next to you.
You looked at him surprised, "What?"
"You fucking heard me, I'm not saying it again." He picked up his pace. You felt kinda giddy.

Sitting back down in your chair, Present Mic was now teaching and talking. He looked at the two of you for a moment before continuing. During the lesson, you rotated a pen around in the air.
"Right, YN?"
You sat up straight, dropping the pen from the air. "What?"
He chuckled, "Nothing, just catching your attention." He sighed and looked around at the class, "Clearly I do not have your attention, so we are taking a break."
You sighed in relief and went to grab your pen off the ground, but Katsuki was already setting it back on your desk. You smiled in thanks, and he just scoffed.

Mic took the class on a walk around the grounds to stretch their legs. In a grassy opening, he had everyone sit back down and said that anyone could ask him questions about hero work. Midorya held the conversation.
You lay back in the grass, relaxing. You looked over when you heard a bunch of giggling to see Kaminari getting ready to roll Kirishima down a hill. You smiled and went over to them.
Soon, the whole class had joined in rolling each other down the hill. Everyone is laughing and screaming. They even convinced Mic to go down a few times.
You looked over to see katsuki agasint a tree, arms crossed. You went over, "Not joining?"
He looked at you, "Fuck no, it's... childish..."
You chuckled, "That's ok sometimes you know." You bumped your hip sideways into him. "Come on, I'll even race you down~"
He scoffed, "Ya right, not happening."
"Fine, that means you forfeit, and I win." You shrugged and started walking back to the rest of the class.
You grinned when you heard him walking angrily behind you.

Next, you two lay down in the grass, and Mina started the countdown. "Ready, set, GO!" You and Katsuki rolled down the hill as fast as you could.
Somewhere along the way, you two ended up getting tangled together and thuded against a fence.
"Ow..." You said, trying to get up, but felt arms around you.
He let go, "Get the fuck off me."
You sat up and sat next to him on the grass.
The Baku-squad was sprinting down the hill with Izuku to get to you both.
"What happened?" Sero said chuckling.
"He rolled into me!" You accused him.
"I did not! I fucking save your ass!"
"You rolled into me and then took me down with you! It was sabotage!"
Everyone around started laughing at your two, and you both stared up at them, covered in grass and dirt. Arguing over rolling down a hill.

"Just like an old married couple~," Mina cooed.
"EXCUSE ME!?" You both yelled.
This only set off more laughter, even Izuku was laughing.
"They've always been like this," Izuku added.
"No, we haven't!" You argued back.
"Mom and Mitsuki definitely have proof!"
You and Katsuki looked at each other and made a silent agreement to hunt down each of the students in front of you.
Your hand shot out, and a stick slammed against their knees to knock them over. Katsuki went for them with explosions.

Recovery girl was really upset when you all walked in. Katsuki and you got sentenced to cleaning up the classrooms. You both quietly cleaned till music started playing. You looked over at Katsuki, who was setting his phone down on the desk.
"It's too fucking quiet."
You nodded, and eventually started to vibe with his music. The next thing you knew, both of you were mumbling along to a song and got more and more into it. He started drumming his fingers on a desk, and you took over vocals. The song ended, and both of you started to chuckle, a bit out of breath. You both smiled at each other.
There was some clapping in the door. Both your smiles dropped as you stared at the group of girls in the doorway.

You felt your face heat up, "What are you guys doing here?"
"You agreed to come with us to talk about costumes, remember?" Momo said.
"Oh, right." You glanced at Katsuki, the boy was in embarrassed shock, "I've still got stuff to help out here."
"No," Katsuki spoke, "I got it. Go do costumes."
"What? But I'm supposed to be helping you -"
He glared at you, "Your costume is all fucked up now anyways, so go getting it fucking fixed before I blow your ass up."
"Fine, fine. I'll go." You set your broom down, and as you walked out the door, you flashed him a smile and a quick thank you.