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

♦ Knocked (Gaster x Sleepy! Reader)

You've never been so tired in your entire life. You thought that it was your body's way of getting back at you for not letting it rest for over a week but you couldn't help it! You were a nightowl, you always slept late, and a certain skeleton always called you out on it.

"______, for God's sake, go to sleep," Gaster spat at you begrudgingly as he examined blueprints of the CORE.

"... But I'm not," you yawned, "Tired."

"An excessive lack of sleep can cause fatigue and thus, make you unable to properly handle daily tasks. Such as bathing."

"Oh, shut up. I'll be fine. I just need to eat something first. Haven't eaten anything since yesterday."

He put his papers down. "This is a very unhealthy and inconvenient lifestyle you're choosing to live by. Being my assistant doesn't mean you can do whatever your heart desires."

You never liked it when Gaster nagged at you, even if he was right.

"Calm down, Gaster. I promise, I'll get it together. I'm sorry I've been a drag lately. It's just that... I'm not used to constantly waking up early and sleeping on a schedule 24/7. It's different for me."

"Primitive human minds can't comprehend "change" the way monsters do. They naturally adjust to "different". But in this instance, "different" isn't sitting around in your food-stained shirt doing absolutely nothing to even give the slightest snippet of an idea."

You felt anger build up but you gave it your all to try and let it subside.

"I'm doing the best I can! Can't you see that? It's not my fault I get tired easily!"

"Well, it sure as Hotland isn't mine!"

"... Okay. Gaster, I don't want to hit another rough patch like we did before, so I think I'm going to head to bed before we start hating each other again." I started for the exit.

"It's a bit too late for that, I'm afraid."

Clenching your fist, you exit the door and head for your room. Though, unfortunately, you didn't make it very far; due to your sleepiness and fatigue, you fell face first onto the cold, tile floor and knocked yourself asleep in the process.

Alarmed by the sudden thud in the hallway, Gaster got up from his chair and went to investigate.

Finding you'd dropped almost dead in the hallway, a light blush dusted Gaster's cheekbones and he sighed.

"You never listen to me," he grumbled as he used his magic to lift you.

Eventually making it to your room, Gaster gently placed you on your bed. Staring down at you, he still felt quite annoyed. Though, he couldn't help but slightly soften as he watched you sleep.

You were so still, so relaxed... so peaceful. A dark blush crept again to Gaster's cheekbones but he quickly dismissed the juvenile thought and proceeded to tuck you in.

"... Thank you... Gaster...," you suddenly uttered drowsily, your voice barely above a whisper.

Gaster slightly flinched at your words, unsure of what to make of the situation. Despite that, he reluctantly gave a small grin, something both him and you thought was impossible for him to achieve.

"... You're welcome," he replied softly as he turned the light off and closed the door.