A/N: Just a quick one shot I wrote in under an hour. I wrote it fast, so apologies for any grammar mistakes. It's short, sad, and sweet. I hope ya like it!
All three of them sat on the couch with a movie playing in the background. Papyrus had fallen asleep, Frisk's eyelids were drooping, and Sans sat huddled in the corner, his eyes elsewhere. Placing his skull in his hands, he sighed and closed his eyes. Memories raced through his mind: meeting Frisk, Frisk's genocidal runs, Frisk's pacifist runs, Papyrus' death, his own helplessness to save everyone… Sans shuddered.
Suddenly he felt a tug on his jacket. Jumping slightly, he glanced down at the couch. Frisk sat looking up at him, concern written across her face. "You okay, big brother?" she asked softly.
The skeleton put on his signature grin. "Oh, of course, kid. I'm fine."
"You don't seem fine."
His grin grew smaller. "Heh… you know what, kid? I'm exhausted. Just finish the movie without me, okay? I'm off to bed." Hopping down from the couch, he trudged out of the living room and up the stairs. The soft closing of a door let Frisk know he was in his room.
With a quiet sigh Frisk turned her eyes back to the TV screen.
Frisk tossed and turned in her bed, unable to sleep. Frustrated, she sat up and stared around her room. A soft glow from her night light filled the room with a faint shine, casting shadows on the wall. Sighing, she began to fiddle absentmindedly with the corner of her blanket.
Suddenly a faint sound caught her ears. She cocked her head. Was that… a whimper? Curious and determined to solve the mystery, she threw back the covers and slid out of the bed. Cracking open the door, she set off down the hallway.
First she checked on Papyrus. He slept peacefully in his racecar bed. Next she peaked into Sans' room.
He laid on his bed, cocooned amongst his blankets. His jacket hung peacefully on his bedroom. At first the skeleton didn't make much movement. His chest rose and fell with steady breathes, but eventually… he uttered an unhappy noise.
His quiet whimpering was not loud or very frequent, but Frisk still heard it. Occasionally he tossed and turned, burying himself further in his blanket nest. After many minutes he suddenly shot up with a gasp of surprise, eye sockets open and glancing wildly about the room. His gaze fell on Frisk and he smiled softly. "Oh… hey kid," he murmured. "What're you doing up?"
Frisk padded over to his bed and gazed up at him with a curious expression. "Nightmare?" she asked rather forlornly.
Sans titled his head and crossed his bony arms. "Oh… uh… " He suddenly faked a grin. "I'm fine, kid."
Frowning, Frisk tugged on his shirt. Her face told Sans she did not believe a word he said.
The skeleton gulped. "Well… ok, yeah. It was a nightmare, but I'm fine now. We all get nightmares once in awhile, don't we?" He smiled again.
The child suddenly climbed onto his bed and sat down, facing Sans with her knees crossed. "You're not fine," she stated softly.
Sans' face fell. "Alright, ya got me, kid." He paused.
She stared at him expectantly.
"Well..." he began slowly. "I've just been… remembering those times Papyrus died, and… other things." His hands were trembling now and he quickly turned away from Frisk's sad face.
"I'm sorry," she murmured. "I… didn't mean to kill them." Tears crowded her eyes.
Sans turned back to Frisk. "Hey kid," he began. "Don't be so hard on yourself. It wasn't you, it was Chara… don't be sorry." A droplet trickled down Frisk's cheek. Sans felt his own eyes water. "Oh, kid… please, don't be like that. It wasn't your fault..."
The child was now staring at the blankets, wiping her face with quiet whimpers. Bad memories flashed through Sans' skull again: his brother's death, Chara's evil stare…
Suddenly the skeleton buried his face in his bony hands. Wetness graced his fingers. He couldn't take it anymore. He's spent so long, too long bottling up his feelings.
He felt tiny arms wrap around his torso, clutching his shirt. Frisk buried her face in his shoulder. Sans encircled his own arms around her, tears now flowing from his eyes. "I-it's ok, kiddo," he mumbled, though his voice barely sounded convincing. He hiccuped and squeezed the little girl tighter.
They stayed like that for several long moments, comforting each other. Frisk's small voice spoke, muffled by Sans' T-shirt. "It's ok now, big brother. You don't have to be sad anymore."
Through his tears, Sans couldn't help but smile. The little kid was so kind, so determined. How could he have ever wanted to harm Frisk before this? He closed his eye sockets, refusing to let go of his surrogate sister, murmuring, "Thanks, kiddo."