Notes:

I just want to say: This is not Frans. Frisk is a kid. Sans is an adult and a big brother/uncle figure to Frisk.

Yeah, so, I realize this is the most unoriginal thing I could write, but... I was tired, and I wanted to do it anyway. I don't have anything better to do.

Thanks for reading!

Frisk gasped and shot upwards. They glanced around wildly. Their brain felt foggy. They couldn't think straight. They only knew they were in danger. They had to run. They couldn't stop or else she would catch and kill them! They had to. They had to! They…

Frisk groaned and dropped back onto their bed. It was just another stupid nightmare. Their nightmare had felt so real this time. They had been able to feel the humidity on their skin, smell the soft scent of water and algae, hear the pounding footsteps behind them. They curled up into a ball and clutched onto their side, feeling phantom pains of a spear lodging itself into them. Whenever they tried to close their eyes, they saw the monster's terrifying face. Her mouth was curled up in a snarl, revealing her yellow teeth. Her eyes were filled with hate and desire to kill the human in front of them.

Frisk liked Undyne. They liked all the monsters now that they had befriended them. They had chosen to get to know the monsters and forgive them even after all they had done to Frisk. Even so, none of it changed that almost all the monsters they called family had killed them at one point or another. Papyrus was one who hadn't, and even he had knocked them out and locked them up in their shed. Nightmares of the battles they'd had with their friends plagued Frisk every night. They were too scared to go to any of the monsters for comfort. What would they tell them? They didn't want to make the monsters upset with them for bringing up all the times they had tried to kill them (monsters didn't remember the times they had killed Frisk). There was no one to go to, so Frisk comforted themselves when they had nightmares, often staying up most of the night. They were so tired. They didn't know what to do.

Well, there was one monster they could go to. There was one monster who hadn't killed or fought them before. He wouldn't become upset if Frisk told him about their nightmares. Nothing seemed to be able to upset him. He probably wouldn't even mind they were waking him up in the middle of the night.

Frisk bit their lip and closed their eyes to try to go back to sleep, not wanting to bother anyone if they could help it. They jumped out of bed when they had a vision of a spear soaring towards them. They couldn't keep putting up with this. The monsters were starting to notice something was wrong. Frisk had trouble keeping their eyes open in the morning. They fell asleep in lessons and were always out of it. They needed to get help.

Frisk padded down the hallway towards their friend's bedroom. They stood outside and tried to gain some courage. They held their fist over the door and rested it on the wood. They gulped nervously and knocked. They didn't wait for an answer. They would lose any audacity they had gained if they did. They opened the door and stepped inside.

Sans was awakened as soon as the knock sounded. He listened to the door creak open and counted the footsteps. He knew they were Frisk's just by the sound of them: soft and timid. 1...2…3…4…5…6… The footsteps stopped when the kid arrived at the side of his bed. He rolled over to face them, placing his usual grin on his face.

"hey, kid. what's up?"

The kid stared at him for a moment and then looked up. "The ceiling." They sounded so solemn. Sans had trouble telling if they were joking or being serious. Knowing the kid, he was inclined to believe they were being serious.

"yeah, true, but i mean how are ya doing? did ya come to kill me in my sleep?"

Frisk shook their head so wildly Sans didn't know how it stayed on their neck. "No!"

"ok, ok, good to know." Sans winked to make sure the kid knew he was just messing around with them. "what's eating you then?"

"Wha…what?" Frisk tilted their head. Their brows furrowed.

Sans held back a sigh. "how are ya doing?" he repeated. "or is waking others up in the middle of the night a normal occurrence for ya?"

"Oh…" Frisk shifted. Their brown eyes surveyed Sans nervously. "I… had a nightmare… I can't go back to sleep."

Sans blinked. "you… did ya get lost on the way to tori's room or something?" He kept his tone light-hearted, but he was curious. The kid had a nightmare, so they came into Sans' room. None of that added up or made sense to him.

"I… No…"

"huh, okay. what do ya want then?"

"I… I don't know…" Frisk took a step backwards. "I… should leave. S-sorry."

Sans watched the kid turn around and head to the door. Frisk had come to him because they'd had a nightmare. They obviously came in with a reason in mind. They weren't the type of kid to wake him up in the middle of the night for no reason. Now, why the kid came to him instead of all the other monsters in the house was the mystery. Toriel or Papyrus seemed like way better choices. They were both good at comforting kids. A skill Sans couldn't brag to have. He could only try.

"hey, kid, wait."

Frisk stopped with their hand on the doorknob.

"did ya… want to stay here for a bit?"

Frisk turned around. They stared at Sans for a long time, shock registering on their face. They nodded. "Can… Can I?"

"yeah, sure. c'mere." Sans held the blanket up for the kid. They slowly stepped towards him. They watched him, trying to decide if this was a trick, and then crawled into the bed. They settled themselves at the very edge of the bed, as far away from Sans as possible. They gave Sans the space they thought he wanted, but they would fall off if they moved.

Sans dropped the blanket over them. He noticed how tense and nervous they were. They seemed to be reconsidering their choice. This wasn't going to help them any if they were on the edge, figuratively and literally. He'd just have to do something to fix that. "what's a nocturnal horse called?" he asked, grinning with anticipation.

The kid shifted to face him. "What?"

"a nightmare."

"Oh… haha…"

It was dark, but Sans was still able to see the soft smile that spread on Frisk's face. Jokes always worked. "do ya want to talk about it?"

Frisk's gaze dropped. "You won't tell anyone, will you?"

"nope, my lips are sealed."

"You don't have any…" Frisk trailed off, deciding it would be better not to say anything. "Promise?"

"aw, bud, you know how i hate promises."

Frisk winced. "Oh, sorry. You don't have to."

"nah, it's okay. i'll make an exception just for you, frisk." Sans winked. "won't tell a soul. promise." The smile that lit Frisk's face was a good reward for the promise.

"Okay, I'll tell you… I dreamed… Undyne was chasing me… She killed me…"

ah, now this all makes sense… The kid was alive in front of him, but Sans knew that wasn't the case in all the timelines. They had faced many trials and scares on their adventure- an understatement. They were lucky all they had were nightmares.

"i got it," Sans said, the only hint he was going to give that he knew exactly what Frisk's had faced and understood exactly why they were scared. "can't blame ya for being scared, kiddo. undyne's intimidating when she tries not to be, forget about when she is trying."

"Yeah…"

"don't forget, the fish lady that tried to kill you… is the same one who burned her house down trying to make spaghetti."

Frisk snorted. "Yeah, you're right there."

"yeah, so next time you have one of those dreams… just imagine yourself attacking her with spaghetti."

They were both quiet as they imagined the scene Sans had offered Frisk. A soft peal of laughter from Frisk cut into the silence moments later. The thought was so absurd, they couldn't not laugh at it.

"Okay… I'll do that… Thank you." Frisk scooted towards Sans. They rested their forehead against his side. He jerked from surprise, but he relaxed as soon as he looked down at them. He was reminded of Papyrus when they had been around Frisk's age. Papyrus would sometimes have nightmares and want to nap with Sans. He would always start out on his side of the bed, and then end up pressed against Sans.

"no problem, kid." He slowly moved to brush his fingers through the kid's hair. Frisk was encouraged by the touch and moved so they were fully nestled against him. Warmth and cold didn't effect Sans, but he could feel the difference. He felt the warmth radiating from Frisk's body. It made the kid feel that much more alive. "night, frisk."

"Good night, Sans." Frisk closed their eyes. A peaceful sleep greeted them within minutes, evident by their slow and even breathing.

Maybe Sans wasn't as bad at comforting kids as he thought.