"Katsuki get your ass down here!" Mitsuki yells as her husband rocks their daughter next to her.

"Honey please don't yell with the baby near you." The said man requests quietly.

"What do you want, old hag?" Katsuki yells back as he walks down the stairs.

"We need you to watch your sister while we go out." Masaru responds and hands the girl to her brother.

"What? But I have people coming over."

"She won't be too much of a hassle Katsuki. Just put her in the playpen."

The blonde boy grumbles as he walks away.

"Money is on the counter Katsuki." Mitsuki yells as her and the hubby leave.

(Y/n) giggles and cups her brother's face.

"Damn old hag." The boy grumbles and carries his sister to her room.

He puts her in the playpen then carries it to the living room.

(Y/n) rolls around and giggles.

"Stop moving." Katsuki grumbles as he sets her down.

The doorbell rings causing the blonde to groan.

He goes to the door and opens it.

"Hey Bakubro!" Kiri greets.

"Hey shitty hair."

"I didn't realize how rich you were Bakugou. Your house is huge." Denki comments.

"It's nice here. I'm still surprised you let us come over." Mina adds.

"Whatever extras. Everything is set up in the living room."

The three stop suddenly at the sight of the playpen.

"You have a baby Bakugou! Since when have you had a girlfriend?" Denki questions as he runs over and looks down at the baby.

"She's so cute!" Mina squeals.

The redhead looks at his best friend. "You have a kid?"

"No! She's my sister you idiots." Katsuki yells, annoyed.

Mina picks up the baby and bounces her gently. "How does a grumpy boom boom boy have such a cutie for a sister?"

"Shut up." The blonde grumbles.

"I think I'm gonna ditch you three boys. The girls are gonna have some fun."

"Mina be careful. She's just a baby." Kiri suggests.

"Raccoon eyes you better bring her back in one piece. The old hag would murder me if something happens to her."

"Bakugou have some faith in me."

"By the way, what's her name?" Denki asks, sitting on the couch.

"(Y/n)."

"That's a nice name. I bet the boys will fawn over her soon enough."

"Dunce face I will explode your face if you don't shut up."

"Aww Bakubro, you're the over protective brother type. That's so sweet."

"Shut up Kiri. It's not like that."

"It's exactly like that." Mina and Denki say in unison.

Small explosions come from the blonde's hands.

Unfortunately this causes (Y/n) to cry.

"Way to go bro. You made her cry." Denki teases.

"Shut up Dunce face!"

"Don't worry. I'll calm her down." Mina assures as she walks upstairs.

"While she does that should we get to it down here?" Kirishima offers.

After a while, and the guys were having a good time, Mina comes back down.

"We're back~" the pink girl sing-songs.

The three look at their friend and their eyes widen.

Katsuki's in horror and the other two in surprise.

Mina changed into one of Mitsuki's old dresses.

(Y/n) is in full makeup and a cute dress as well.

"What did you do to my sister Mina?!" Katsuki yells, standing up quickly.

"She's adorable." Kirishima comments.

"And Mina you look great too. I can only imagine what Mitsuki would look like in it." Denki whispers that last part to himself. (😏😉)

"She's a baby. She doesn't need makeup. And this dress..."

The friends look at their friend as if waiting for him to finish.

A small blush covers his cheeks.

His parent's fashion advice must've rubbed off on him.

"Nevermind! Just go change back. I'll clean (Y/n) up." He takes his sister back.

Denki and Kirishima smirk as they watch the other two walk away.

Mina is the first to come back down. "I thought she was amazing."

"Oh she was. I just think Bakugou was embarrassed." Denki responds and rubs her back.

"He's probably not used to his sister being fawned over by his friends." Kiri adds.

Katsuki sits (Y/n) on the bathroom sink and wipes the makeup off.

The baby looks up at her brother and tips her head to the side.

Her hand reaches up but he puts it back down.

"You're such a pain in the ass." He whispers.

She giggles softly, eyes closed.

He carries her to her room and changes her into pjs. "You don't need makeup or a pretty dress. You especially don't need others to tell you how amazing you are. You're powerful and badass and don't need anyone."

She buries her face in his chest and yawns softly.

He smiles softly and holds her close. He rocks her slightly and hums softly until she falls asleep.

She lays on her back, sucking her thumb.

Katsuki pulls the blanket to her chin and makes sure her stuffed bear is next to her. He kisses her forehead then walks back down to his friends.

"Whoever wakes her up dies."

//I wanna make more one shots where (Y/n) is a baby or young. So they'll just be baby (y/n) 1-2-3 etc or young (y/n) 1-2-3 etc