Welp...Here I am, writing fanfics for Undertale, of all things, but whatever. I had this thought pop in my head about Papyrus and Sans arguing, and I couldn't get it out of my head. All I can say is: I'm sorry. Also, this'll be a two-shot fanfiction.

I should also mention:

*Sans will only speak in italics.

*Papyrus will only speak in bold.

Considering that I can't really change things so they speak in their respective fonts, I figured this would be a good enough compromise...

so, uh...let's begin.

It was just another nice day on the surface. The sun was shining in the sky, the snow was melting from the ground...it was just a normal day for both humans and monsters.

Frisk was standing in the kitchen with their adoptive mother, Toriel. They were helping her create a butterscotch pie. The goat-like monster was looking over a list on the counter.

"Let's see now...Next we need to add two cups of milk."

Frisk obediently walked over to the fridge. They pulled out a milk carton and handed it over to Toriel. The monster grabbed the milk from Frisk and patted them on their head. "Thank you, Frisk."

Suddenly, the duo could hear the front door slam shut, followed by arguing.

"OH MY GOD, SANS! WOULD YOU JUST LISTEN TO ME FOR ONE SECOND!?"

"TIME'S UP!"

"Guys, can we stop fighting?"

"YOU STAY OUT OF THIS!"

Frisk and Toriel walked into the living room. The human frowned, they could see their adoptive brothers arguing over something. Between the two brothers was Undyne, who was trying to stop them from fighting. Frisk noticed that Sans had a bone in his hand.

Undyne had one hand on Papyrus' chest and another hand on Sans' skull. "Seriously, would you dorks just stop?"

"NOT UNTIL HE STOPS TREATING ME LIKE A CHILD!"

"NOT UNTIL YOU STOP TREATING ME LIKE GLASS!"

"FOR GOD'S SAKE, SANS! YOU COULD'VE BROKEN YOUR SPINE!"

"SHUT UP!"

Undyne pushed the brothers further away. "You're both acting like kids! Knock it off!"

"whatever!" Sans threw the bone at Papyrus' skull and headed upstairs. The taller skeleton trembled with rage. He started yelling louder then usual, his eyes were glowing orange. "YOU KNOW, AT TIMES LIKE THIS I WISH I DIDN'T HAVE A BROTHER!"

"SAME TO YOU, BUDDY!"

"SCREW YOU, SANS!"

"BURN IN HELL!"

Papyrus' bones rattled violently. He stomped through the living room, dropping himself onto the couch. He was seething with rage.

Frisk, Undyne, and Toriel were standing there awkwardly. It was eerily silent for a few more minutes until they heard the sounds of objects being thrown upstairs.

"SANS, YOU BETTER NOT BE MAKING A MESS UP THERE!" Papyrus snapped. This only made the sounds grow louder. Papyrus summoned a bone in his hand, racing upstairs to continue fighting with his brother. "THAT'S IT, YOU'RE DUST!"

"Excuse me," Toriel said as she raced upstairs, concerned about the two brothers. Frisk walked over to Undyne. Their hands were behind their back. "What happened?"

Undyne awkwardly rubbed the back of her head. "Well, Sans thought he'd try sledding down the mountain on his bike."

"That sounds cool, actually." Frisk thought out loud. Undyne nodded in agreement. "Yeah it does, but...given how frail Sans is, it would just be a matter of time before Papyrus freaked out about it. One minute Papyrus is trying to convince his brother to wear a helmet...Next thing you know, they're trying to break each other's bones."

Frisk had a look of concern on their face. Despite their differences, Sans and Papyrus usually got along just fine. Sure, there was some nagging and instigating here and there, but there was never any actual fighting.

"Hey, Frisk!"

The human felt Undyne place a hand on their head, she was smiling widely like she usually does. "Don't worry about it, too much. Besides, they'll have to make up, eventually."

The fighting upstairs finally stopped. Papyrus marched downstairs and ran outside, slamming the door behind him. Toriel came downstairs, afterwards. She looked exhausted, her fur was a mess. "I finally got them to stop."

"So what'd you do?" Undyne asked.

"I asked them if they'd like to go for a walk," Toriel replied. "It seems to have worked on Papyrus, but Sans insisted that he'd rather stay in his room." The boss monster started straightening out her fur. "Right now, I believe it's best that we leave them be."

Toriel could feel someone pulling at her dress. She looked down, scooping Frisk into her arms.

"Can't Papyrus and Sans just talk things out?" Frisk asked.

"They will talk when they're ready." Toriel said firmly. "For now, we'll just have to worry about ourselves."

"So what now?" Undyne asked, crossing her arms.

"We were going to make some pies today," Toriel replied, "would you like to join us?"

Undyne shrugged. "Sure, why not?"

"Splendid~!" Toriel said happily as she walked into the kitchen. "But please...don't set the kitchen on fire."

"I won't," Undyne said, chuckling, "Well...no promises, though."

After the pies were baked (and the kitchen remaining only half-destroyed), Frisk decided to check on Sans. They climbed up the stairs to their brothers' room. However, they couldn't help but noticed the room was blocked off by a row on bones, forming a gate.

Frsk tried knocking on the door. "Sans?"

There was no answer. Frisk tried knocking on the door, again. "Hello? Sans?"

Again, there was no answer. The human tried to think a little differently. They tried knocking on the door once more. "Knock knock!"

Once again, there was no answer. Instead, more bones appeared in front of the door, turning the bone gate into a bone wall. Frisk sighed in defeat. "OK, I guess I'll talk to you later!"

Frisk walked down the stairs. If Sans wasn't willing to talk, then maybe Papyrus would talk to them, instead.

Frisk walked downstairs, they could see Papyrus was watching TV. He was watching one of his favorite shows, "Cooking With a Killer Robot." The human sat next to Papyrus, the skeleton started patting their head. "Hello, dear Frisk. How have you been?"

"I-I've been all right," Frisk said, surprised by Papyrus' demeanor. Frisk tried to keep their composure, avoiding eye contact with the skeleton. "Er...I've been meaning to ask you something."

"Go ahead," Papyrus said happily, "Ask me anything!"

"W-well," Frisk rubbed their arm uncomfortably, "Do you think you'll be able to talk to Sans, again?"

"Oh..." Papyrus' expression changed, he looked angry. "Frisk, why don't you leave me alone?"

"But-"

"Frisk, please!" Papyrus was on the verge of yelling, "Never mention that lazy numb skull around me again, do you hear me!?"

Frisk nodded in defeat. They got up from the couch and headed into the kitchen. They sat on one of the chairs, tapping their fingers against the table. They weren't sure what to do. It was funny to think: a kid who freed an entire civilization couldn't even get two brothers to stop fighting.

But of course...maybe Toriel and Undyne were right, maybe it was best to leave them be for now. After all, they couldn't stay mad at each other forever.

Frisk looked over at the counters, noticing how many pies have been created. Snail Pie, Cinnamon Pie, Butterscotch Pie, Butterscotch-Cinnamon Pie...

There was a single slice of pie sitting on the counter. Underneath the plate was a letter. Frisk walked over to the pie slice and read the letter.

"Dear Frisk.

I know you would have wanted some pie, so I left a slice here for you.

-sincerely, Toriel."

Frisk was tempted to eat it. After all, Toriel made the best pies...But maybe it was best to hold onto it for now. After all, the pie might actually be useful for something. At least that's what Frisk assumed. They took the pie and headed to their room.

And thus ends part one: Part two should be up some time tomorrow.

So, uh...see ya later!