*Writing these oneshots fills you with Determination 2 (Undertale AU Oneshots)

♦ You Brat... (Frisk x Older Sibling!Reader) [Fluff]

Word Count: 590
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You, your younger sibling, and Toriel had just gotten home from a full day of running errands. Needless to say, you, being the older and less excitable one, were exhausted. 

Frisk, on the other hand, was full of energy, which amazed you. You'd think even an 8-(or something)-year-old would need more sleep but Frisk was the exception. 

"Alright, my children," Toriel started, heading for the kitchen, "Go play while I make dinner."

*You asked _____ if they wanted to play hide and seek.

You yawned. "Sorry, Frisk, I'm," you stretched your arms up, "really tired. I'm going to take a nap. I'll play when I wake up though."

Frisk pouted. 

*You gave _____ puppy-dog eyes and said please.

You finally got to your room, with your sibling following close behind, and changed into your naptime clothes. 

"I've been living with you for years, Frisk," you told them with a smirk, "The puppy eyes won't work on me anymore."

At seeing you lay down in your bed, Frisk came up and climbed on top of you, playfully hitting your stomach. 

"You brat...," you wheezed, looking up at them. "Get off me. If I turned over on you, you'd be dead." You quickly dragged them down by the head and put their face into the pillow. 

"Is that what you want? To suffocate and die?"

*You struggled to get out of your sibling's grasp...

*...

*But nothing happened.

*No one is happy with this.

"What's that?" you teased, tauntingly putting your hand to your ear, "I can't hear you over the sound of me slowly killing you. Care to speak up?"

*You told _____ to let you up because you couldn't breathe.

"Hmmm... Well..."

These were the moments that few people got to see between you two. Most of the time, both you and Frisk were treated with the utmost respect by the other monsters. Sometimes they forgot that you're human beings. So when it was just you two at home, it was your time to relax and be free of formalities. 

*You threatened to tell them on Toriel.

"Oh yeah? I'd like to hear you try and call for help."

As if on cue, Toriel came into the room, a confused look on her face. "What is going on here?"

You froze and immediately let Frisk up, who was gasping for air. 

"There will be no rough-housing in the house, children. Someone could get hurt!"

"Sorry, mom," you said.

*You apologized to Toriel.

When she left, the two of you looked at each other before Frisk yawned.

You pointed at them. "Ah! See, you are tired. Let's take a quick nap before mom finishes dinner." You lay back down on the bed and got comfortable. 

*You lay down next to _____.

*You tell them that they feel warm.

"That's 'cause I was spending all that energy on you, silly," you teased, closing your eyes, "You got me all hot and bothered."

Frisk cuddled up to you, nuzzling their face in your side. 

Then you got an idea. You wrapped your arms around Frisk.

*You told _____ that they're crushing you.

"What? I can't show my little sibling how much I love them?" You nearly squeezed the life out of Frisk and were amused by the annoyance in their voice.

*You begged your sibling to let you go but they laughed.

"Nope! You chose to take a nap with me and now you gotta suffer by my death hugs."

Frisk sighed.

*You told _____ that they're annoying.

"I love you too, Frisk."