"Hey, Papyrus, do you know where I put the hot dogs? The human took the last thirty of 'em after stacking them on their head."
No response.
"Papyrus?"
Sans scratched his skull in confusion. Pulling his head out from the tall cabinet under the sink, he walked to the doorway and peeked into the living room, only to find his younger brother Papyrus was nowhere to be seen. This definitely took Sans by surprise. Usually the euphoric skeletal monster was watching MTT at this time. But lo and behold, the couch was empty and the TV was turned off.
"Hey, bro?" Sans called out, walking into the living room and looking around. He noticed his pet rock to his right and was shocked to find no sprinkles on it. Or rather, no added sprinkles. Papyrus would usually feed it long before now. There wasn't even a new sticky note with an irritated message next to his sock he still to this day refused to move.
Something strange was going on here, that's for sure. Where on earth was Papyrus?
A sudden thought flashed through Sans' mind, causing his magic to begin to spark upon reflex. What if something happened to him? What if Frisk... What if they...
A loud snort startled the skeletal monster out of his dark thoughts, and his magic was quickly extinguished. He recognized the noise to belong to Papyrus - he felt almost as if he were going to pass out he was so relieved - and detected the source to have come from his bedroom.
"Oh, I see now," Sans chuckled to himself, placing his hands in his jacket pockets and allowing his muscles - or lack thereof - to relax. The younger brother was working so very hard at making sure the house was kept up with. Things having been made harder with Sans' constant lounging around and pretty much getting in his way of work, Papyrus was always up and running to keep the house as neat and tidy as possible if he wasn't cooking spaghetti, recalibrating puzzles, or training with Undyne. The poor monster must've passed out from exhaustion a while ago while Sans was out taking a break at his station in Hotland.
The older brother decided to walk up the stairs - groaning dramatically with each step - and make his way quietly into his brother's room to check up on him. Papyrus hadn't bothered removing his battle body to change into his pajamas before crashing on his race car bed; he wasn't even under his covers, he was splayed out all over his bed. Sans couldn't help but laugh to himself. His brother was such a little goofball sometimes.
A new idea flashed through his head, causing his eternal grin to stretch up into a mischievous smirk. He remembered very well of what had happened about a month ago: Papyrus had tickled him in an attempt to make him cut his lazy habits and work alongside him. Naturally, things went back to the way it was, but only after a full week; Sans did not want to go through that kind of experience again. He was grateful every day since then that Papyrus hadn't tried tickling more sense into him as of yet.
Now Sans finally found the perfect opportunity to get back at his brother.
The skeletal monster's left eye began to glow blue as his powers were activated, and he used his magic to pin Papyrus down on his bed with his arms held above his head. He then walked up to his side and inhaled deeply before blowing a strong raspberry directly in the center of his spine.
The reaction was immediate. Papyrus' eye sockets flew wide open as he let out a loud gasp, and once his mind got a grasp on what was going on he let out a squeal followed by hysterical laughter.
"AAAAAHAHAHAHAHAHA! WH-WHAT'S GOING OHOHOHON? STAHAHAHAHAP!"
"Hey, there, little bro," Sans smirked. "Had a nice nap?"
"S-Sans? What's going on?" Papyrus began to struggle, but his strength was no match for Sans' magic. "Why are you using your powers on me? Sans, let me go!"
"I don't think so, buddy. I've been waiting forever to get back at you for your own little stunt, and now that I have the opportunity I'm not just gonna pass it up."
"That was a month ago!" Papyrus cried, his voice rising with panic. "I thought you'd gotten over that!"
"Then I guess you don't know me as well as you think." Without giving Papyrus a chance to respond, he began gliding his fingers up and down his spine, chuckling as it twitched and squirmed.
"N-NYAHAHAHAHAHA! SANS, STAHAHAHAP!" Papyrus giggled profusely. "TH-THAT TIHIHIHICKLES!"
"No kidding," Sans replied with an amused snort. He began to playfully drum his fingers against Papyrus' spine, sliding his hands up and down to cover the entire backbone.
"EHEHEHEHEHEHE! L-LEAVE ME ALOHOHOHONE! IT'S TOO MUHUHUCH! AHAHAHAHAHA!"
Sans chuckled as he stopped tickling, allowing his younger brother a chance to catch his breath. "Boy, I knew you were ticklish, but I didn't know you were downright intolerable to it."
"I-I am..." Papyrus breathed. "So please stop..."
"Nah, I have a better idea: I'll keep tickling you until you build up the endurance for it!"
"S-SANS, N-AAAGH! AHAHAHAHAHAHAHA!" The younger brother was cut off as Sans resumed his tickling on his spine. He tried to squirm his backbone out of reach, but those tickly fingers always found a way to catch up. "STAHAHAHAP THAT! PLEASE, BROTHER! EHEHEHEHE!"
"Boy, seems like I really am tickling your funny bone, huh?" Sans snickered as he tickled Papyrus' ribs through his battle body. "What's wrong, bro? Can't handle the ticklish Sans-sations?"
"SANS, STAHAHAHAHAHAP!" Papyrus shouted, tugging at his arms in an attempt to protect his torso; Sans' magic held fast however. "DON'T MAKE PUHUHUHUNS! YOU'LL MAHAHAHAKE THINGS WORSE! AHAHAHAHA!"
"Don't think I will, these puns are pretty humerus." Chuckling as he continued tickling Papyrus' ribs, the older brother inhaled before blowing a strong raspberry on his spine, causing the younger skeletal monster to shriek in hysteria.
"AAAAAAAHAHAHAHAHAHAHA! NOT THAHAHAHAHAT! PLEASE STOP, AHAHAHAHAHAHA!"
"Nah, I think you like it. Do you like it, baby bro? Does the widdle baby bones like the tickles?" Sans began to tease in a baby tone as he began tickling down his femur bones, past his knee caps, and down his tibia and fibula bones until he reached his boots. Smirking, he began to slowly remove his boots.
"N-NO, SANS!" Papyrus gasped, struggling to yank his legs away. "Don't tickle my feet, please! I'm sorry for tickling you before! Please let me go, brother, PLEASE!"
"Looks like the Great Papyrus is finally learning the true meaning of de-feet!" Sans laughed. He pulled off his younger brother's boots and immediately began skittering his fingers across his smooth bony soles.
Papyrus' eyes widened in his trademark bug-eyed expression as he let out a scream of laughter before breaking into uncontrollable thrashing and cackling. His feet were way too ticklish for him to stand for long, and already he found himself unable to utter many words through his hysteria.
"S-SA-HAHAHAHAHAHAHA! PLEASE! NO-HAHAHAHAHAHAHA! AAAHAHAHAHAHA! STAHAHAP IT!"
"Tickle, tickle, tickle, baby bones!" Sans teased as he began tickling under his brother's toes. "I'm sure you'll keep this special memen-toe for a long while, hehehe!"
"NYAAAAAHHH! STAHAHAHAHAHAHAP IT!" Papyrus wailed, tears falling down his bright orange cheekbones; he began to fall into silent laughter, his body overwhelmed by the strong tickly sensations. "PLEHEHEHEHAHAHAHA! C-CAHAHAN'T TAKE IT! AHAHAHAHAHAHAHA!"
Sans chuckled a bit, giving his feet one last good tickle - causing Papyrus to let out a silent squeal followed by a loud snort - before finally stopping. Papyrus fell limp with exhaustion as he struggled to catch his breath, giggling weakly over the ghost of the tickling.
"Hehehe, how'd you like that, bro?" Sans grinned smugly at his younger brother. "You gonna pull off your little stunt again?"
"N...No..." Papyrus heaved. "I won't... Not if you're... gonna retaliate... like that..."
Sans gave Papyrus a sympathetic smile as he subsided his magic, releasing his limbs from their grasp. Papyrus gently pushed his older brother off him once he found he could move again.
"Get off me, lazybones," he growled affectionately. "Sheesh, you can be so annoying sometimes."
"Hey, that's my job as your older brother," Sans retorted with a shrug. "Anyway, I'm guessing that session left you pretty exhausted, so I'll let you get back to sleep. Perhaps we can head on over to Waterfall later on and solve those new puzzles Undyne's been telling me about."
"That would be magnificent!" Papyrus exclaimed excitedly. His sudden euphoric burst of energy was evaporated by a yawn, and Papyrus curled up in his bed, smiling as Sans draped the blanket over him. "I love you, brother."
"Love you, too, Papyrus," Sans smiled softly, giving him a loving pat on the head. "Sweet dreams."
Once Papyrus fell into soft snores, Sans quietly backed out of the room, turning off the light, and closed the door behind him.