Chapter Text
The house was mostly empty, but it was theirs. Well, provisionally theirs. Theirs as long as they both remained in their 'qualifying professions' for a minimum of five of the nebulously-defined Underground years. But that wasn't going to be a problem: Papyrus loved his Sentry job and Sans was probably still going to be a post-doctoral fellow in five years, as long as his department head didn't finally get sick enough of his puns to banish him permanently to the Supply Closet of Dead Careers. Although honestly the list of professions was so extensive he was pretty sure he could find a way to get 'suspicious 'dog vendor' to qualify.
Their new home seemed absurdly spacious after growing up in the capital; two stories, some number of basements, and a shed/guest room were all theirs to do with as they pleased. There was even a convenient entrance to the town's high-speed tunnel network!
It was probably going to take quite a while to get the place looking homey; it turned out that a studio apartment's worth of furniture didn't do much to fill up a whole house. They had lots of linens, at least, and an expedition to the dump had turned up a second mattress. For some reason there were always a lot of mattresses in the dump, but hardly any bed frames.
Well, on the bright side Sans was free from teaching obligations for a while, and they were a lot closer to the dump, so he should be able to take a few trips to forage over the coming days and weeks.
Most of their first day in Snowdin was spent meeting a seemingly endless parade of locals. Bunnies, Drakes, Slimes and Dogs all lined up to introduce themselves and drape their house in lights. "Things are quiet here in Snowdin," a Bear monster had proclaimed loudly as he supervised the Dogs who were decorating the Skeletons' roof. "We make up for it by being the brightest town in the Underground. Well, that's politics!"
Late in the evening, when they'd finally seen off their many new neighbours, the brothers settled down on the kitchen floor to eat their supper. Papyrus had constructed a tangy soup out of ingredients from the local store.
"damn, paps, this is the best thing you've ever made!" Sans scooped up a spoonful of the thick, reddish broth.
"YOU ALWAYS SAY THAT," Papyrus complained. "IT CAN'T ALWAYS BE THE BEST THING I'VE EVER MADE."
Sans hummed in pleasure as he tipped another spoonful into his mouth. It was savoury and sweet all at once, with tender chunks of root vegetable. "sure it can! you get even greater every single day!" He winked to really grill his brother's cheese.
Papyrus fastidiously set his bowl on the tiles, spoon and fork neatly posed sixty degrees apart, and then clapped his hands over his face. "SAAANNNNSSSS," he wailed, "YOU'RE EMBARRASSING ME!" He peeked out at Sans through his fingers. There was a faint tangerine blush on his cheekbones, but Sans could see that Papyrus was smiling behind his hands.
"aw, there's nothing to be embarrassed about, little bro." Sans patted his knee comfortingly. Papyrus had such long legs that his knees were pushing into Sans's personal space, almost touching him, even though Papyrus was sitting an arm-length away. "c'mon, what's the secret ingredient?"
Papyrus nyehed softly and peered at Sans. His knee shifted under Sans's hand, bumping into Sans's femur. "TOMATO PASTE. THE STORE HERE HAS COPIOUS SUPPLIES OF IT! THE BUNNY MONSTER RUNNING THE STORE TOLD ME THAT SOMEONE TRADED THEM A WHOLE CRATE OF IT A FEW YEARS BACK AND THEY HAVE BEEN STRUGGLING TO DIVEST THEMSELVES OF IT EVER SINCE."
Sans settled back against the wall, happy to listen to his brother's rambling, eat his meal, and enjoy the familiar embrace of Papyrus's ambient magic pressing against his own.
"OF COURSE I, THE GREAT PAPYRUS, HAVE ALREADY THOUGHT OF SEVERAL POTENTIALLY INNOVATIVE CULINARY USES FOR THE INGREDIENT. STEW, OF COURSE. SOUP. SAUCE. RAGOUT…" he leaned closer, browbone arching, "OR EVEN, PERHAPS. RAGU?"
"sounds like a soup-er plan, bro."
"NYEH! AND JUST LIKE THAT I AM BACK TO BEING ANNOYED WITH YOU."
"you're smiling, tho',"
"I CAN'T HELP IT IF MY FACE IS STOCK THIS WAY!"
They finished up their meal amidst companionable bickering. Papyrus washed the dishes because their sink was built tall enough for Sans to walk under and he hadn't had a chance to adjust it yet. And also because Sans's dishwashing was significantly below Papyrus's minimum acceptable standard in both aptitude and attitude.
So, while Papyrus bustled around like a kitchen dynamo, Sans slumped against the door frame, occasionally using gravity magic to slide things out of Papyrus's reach when he wasn't looking. Dishes gave way to general tidying, while Sans relocated to the living room to peruse the Underground's single reputable Physics journal in search of articles that needed rebuttals. And when Snowdin's daily cycle of snowlight reached its deepest gloom, Sans left Papyrus working on plans for new traps and headed upstairs.
"I WILL RETIRE SHORTLY, BROTHER—AS SOON AS I HAVE DEVISED A SOLUTION TO THE HEAVY TRIPWIRE PROBLEM PLAGUING THE TRAPS IN SECTOR 9."
Sans paused at the top of the stairs, draping himself lazily over the newel post. "you know, you don't really need to come to bed at the same time as i do anymore, now that you have your own room. it's not like you're going to wake me up."
Papyrus gave him a look that Sans wasn't quite willing to interpret. "BE THAT AS IT MAY, MY NOCTURNAL ITINERARY REMAINS UNCHANGED."
"whatever you like, bro." Sans shrugged, picked himself up off the railing, and sauntered into his room.
With the door firmly closed behind him, Sans carelessly dropped his clothes a piece at a time while he walked across the empty expanse of his bedroom. He didn't have a dresser yet, just a closet with a dimensional box in it, and he reveled in the luxury of standing there in his bare bones to pick out a loose shirt to sleep in. Snowdin nights were a lot chillier than New Home, so he quickly tip-tapped his way to his mattress and climbed in under the cozy blankets.
So much space! He stretched extravagantly like he was making a snow angel, stubby arms and legs flirting with the edges of the mattress, before he grabbed his pillow and curled in tight around it. He snuggled into the warmth and softness, breathing deep of the fresh scent of clean linens. For a guy who considered sleeping more than four hours in a night to be a sign of chronic laziness, Papyrus really had mastered the entire science of bed linens. A part of Sans missed the reassuring pressure of his brother's ambient magic pressing against his own; but he pushed that down in favour of enjoying the unprecedented freedom of a completely unoccupied bed.
When he got tired of jiggling around like a talkative moldsmal, he rolled over to rest his back against the wall. He caught the blankets with his toes and tucked them tight around his legs like a little cocoon, sighing into his fluffy pillow. His bed was against the internal wall, the one that separated his space from his brother's room. He could feel the vibrations of movement in the other room through the wall as Paps moved around in there, a comforting reminder that his brother was present, safe, and provided for. Heh. Must not have gotten too tripped up by that trap problem after all.
Sans let his sockets smooth closed.
A hand drifted beneath the covers, skimming over the generous curve where his nightshirt bulged tautly with the pressure of his ambient magic. He circled that hand, enjoying the smooth glide of phalanges over cloth. A flurry of shivers chased themselves through his bones until he purred and stretched beneath the blankets like a cat.
He was pretty sure that for once, he was relaxed and comfortable enough to just drift right off to sleep without needing a helping hand.
On the other hand (heh) here he was, bed all to himself, finally finding himself with the privacy he had been craving for so many nights in that cramped New Home apartment. Was he really going to waste it? Of course he wasn't.
He delved confidently down into the space between his ribs and pelvis, where a fleshy humanoid might have a soft abdomen to pet. Sans just had barely-perceptible magic there, but the slow stirrings of his hand made it feel lovely and warm. He pressed his fingertips into the complex curves of his vertebrae, nudging the edges of the disks. The spine wasn't an erogenous zone, per se—it wasn't like his pelvis, or certain parts of his rib cage close to where his soul manifested. Here, context mattered—a casual touch could just be that, casual. Like if his brother innocently rested his hand there during a hug, it wasn't going to get him all hot and bothered. But a gentle caress, trailing ticklish along the tight gaps where the intangible phase of his body resided, made his ambient magic roil and smoke. Scraping his distal tips over the bone just so could make his whole spine rattle. A pinch delivered just right to a tight disk made him gasp in a startled breath.
Sans slid onto his back, one knee left propped against the wall, femurs splayed casually. He had time, he had space, so why not celebrate by doing something a little more adventurous than usual?
Magic was already circulating down his spine, ready to manifest, so he slowed his roll a bit. From pinching, he eased back to just skittering his fingertips over his spine. He didn't quite let himself relax, but he didn't escalate either. Sans could feel his magic pooling warmly in the cradle of his pelvis, simmering quietly like his brother's delicious soup. don't think about papyrus.
Through the wall, he heard blankets rustle, the creak of a bedspring - Papyrus must be going to bed. Sans had been at this for a while.
So he willed more magic to join that building pressure. His pelvis grew first hot and then humid as excess magic shed across the bone. There was a bit of an art to it, letting more and more magic collect there without allowing it to fall into a physical form. Magic was fundamentally tied to intent, and his Intent right now was very much aimed at constructing a framework to help him process the pleasure rolling through his bones. It was a struggle to keep his magic from blooming, but it was also rewarding. He persisted.
He could still hear movements through the wall—rustling, creaks, mild thumps. Rhythmic bumps.
Sans strummed his fingertips down his spine, flirting with the place where spine became sacrum. The sensation of bone on magic-infused bone almost ticklish in its intensity; he had to pause to breathe. The tension simmered hotter. He directed more little sips of magic back into the bone, heightening the sensitivity until he almost couldn't even stand to touch it. Breaths out turned into sharp little grunts, his voice going high and thin.
An answering moan sounded through the wall.
"fuck," Sans gasped. His concentration broke. His back arched as he lost his tenuous hold on the roiling magic at his core, and it manifested all across his pelvis in such a sweet rush that he felt his eyelights fuzz in his sockets.
How had it never occurred to him that Paps was going to bed, but not necessarily to sleep!?
Well, no helping it now. He could tell that his magic had solidified into some physical manifestation, but he wasn't quite able to figure out exactly what it was. His pelvis felt… odd. He could detect neither the tense warmth of internal genitalia resting between his broad hips, nor the pleasant throb of one of his dicks. Instead, there was a sort of heavy, tingling tightness, stretching from pubis to iliac crests like he was wrapped in heavy plaster that was somehow also sensitive.
He must have been quiet for a while, because there was an inquisitive "HMMNYEH?" from the other room, followed by, "WHY ARE YOU SUDDENLY SUSPICIOUSLY QUIET, SANS?"
"'m fine, paps!" Sans called reflexively. "just uh…" he lifted the blanket to get a look at himself. "startled… me…"
huh.
"VERY WELL, IF YOU ARE SURE. LET ME KNOW IF YOU NEED ANY ASSISTANCE."
"sure thing, bro."
Well, this was different.
The space beneath the sheet was dimly illuminated by the calm, blue glow of magic shedding off of him. There was a layer of ectoflesh covering the bones of his pelvis… except… except it wasn't exactly a layer. At least, not a smooth layer. It was more like a collection of small, rounded bumps, densely packed together around his centre, and more sparse as they spread out toward his femurs. Around his sacrum they were so tightly clustered that they mounded up into a quivery hill.
Through the wall, Sans could hear that particular symphony of noise that indicated Papyrus had gone back to… whatever he was doing.
don't think about papyrus.
Well. This might not be exactly what Sans had been planning but then again, he was quite aware of the versatility of the skeleton package. Might as well at least see what it could do.
He gave his hips a little wiggle. The buds jiggled a bit, but it didn't feel like much of anything other than shaking his booty. He selected an outlying bud on his right greater trochanter, and tried touching it with one cautious distal phalanx. The little bump was about the same size as the tip of his finger, and its surface slipped a little under his finger's pressure. Like there was some softer material inside, under the firm skin. It also felt pretty good; not intensely so, but kind of like stroking his sensitive ribs through the buffer of a hoodie. So obviously he did it some more, rolling the ball of his phalanx over the little nub.
A little magic shed, slicking his movements. It also seemed like the ecto beneath his fingers was… stiffening? A few more rubs and he was certain of it. The little bump was changing shape, too, growing a bit convex under his touch. It became more cup shaped as he watched, accepting the pressure of the fingertip sinking into it. Tiny, tiny little tendrils arose in a ring from the edge of the depression, too small to even wrap all the way around his fingertip. They just sort of waved cutely, tickling the sides of his phalanx.
His ecto always had something of an opalescent quality. It didn't glow, exactly, not the way shed magic did. It was more like the light was trapped somewhere inside it, ricocheting about without ever quite escaping. As he toyed with it, this little bud seemed to gather that light into itself. He moved his finger to stroke along the side of it, watching as a thick bead of glowing liquid magic gathered in the depression. It quavered, like a dewdrop fighting the pull of gravity as it hung suspended on the point of a leaf.
It still didn't feel particularly intense. More like petting the high crests of his hip bones than flirting with his sacral foramina. And he… kinda wanted some intensity right now. Through the wall, he could hear that Papyrus's rhythm had increased in tempo. Was he imagining that he could hear the sound of bones moving over something slick?
Sans slid his finger back up the side of the bump, to where the magic was gathering—
"ahh!"
A short, sharp burst of pleasure struck him when he nudged it, like a single hard clench of deep muscle, and the bubble of liquid magic flashed instantly to vapour. Like a tiny, localized orgasm that was there and gone before he could even brace himself for it.
"—SOUNDS LIKE YOU ENJOYED WHATEVER THAT WAS." Papyrus was talking to him through the wall.
"oh. uh, yeah, paps."
The bud that Sans had been toying with seemed spent now, little tendrils withdrawing as it shrank back against the bone. Well, there were more where that one came from. A lot more.
Sans picked a spot inside the wing of ilium where a few of the buds formed a small cluster, and circled over them with the tips of three fingers. He hummed at the pleasant warmth that spread out through his bones, and heard an answering rumble through the wall.
"you know, the thing about moving to a house and getting our own bedrooms was supposed to be that we got some privacy, bro." He tried to make his tone sound teasing, but it came out breathless as he worked the cluster through the same stages of firming, contracting, and tendriling as the first one.
"WELL YES, BUT IT'S NOT LIKE YOU SOUND-PROOFED."
"that's true," Sans admitted. He watched as these buds each welled up with liquid magic too, bones vibrating in anticipation.
"AND YOU DID HAVE YOUR CHOICE OF WALLS TO PLACE YOUR BED AGAINST. YOU DIDN'T HAVE TO PUT IT ON THE OTHER SIDE OF THE SAME WALL AS MMM, MINE."
"hnnggg-" Sans didn't even have to touch this time to make the buds… release. His shivering was enough to dislodge their magic, and he made a low, choked noise as the vapour lifted away. Some of these beads didn't immediately dissipate, instead hanging above him like tiny stars with no particular regard for gravity or decency.
Papyrus continued, undeterred. "AND JUST LISTENING IS OKAY, RIGHT? WE'RE NOT EVEN TOUCHING AMBIENT MAGIC THIS TIME."
"yeah, it's fine, paps, it's okay." Sans groaned through the after-shivers. That had been, what, five? Five out of maybe a hundred more.
Throwing caution to the wind, Sans plunged both of his hands into the cradle of his pelvis. The buds were gathered as thickly as a bunch of grapes over his sacrum, and Sans went at them with all of his phalanges.
"I LIKE IT. YOUR MAGIC. IT'S SO COMFORTABLE AND ALIVE, LIKE A BLANKET THAT COULD SINK RIGHT THROUGH MY BONES AND KEEP ME WARM FROM THE INSIDE."
Sans swore. With this many buds all around both of his hands, any movement of his phalanges stimulated something. He couldn't keep track of which ones were close to spending, and he was racked with a constant string of violent shudders as they went off by ones and twos.
"I CAN HEAR YOUR BONES RATTLING," Papyrus added conversationally.
Sans struggled to paste his words together between gasps. "i summoned something new. it's pretty uh, pretty great actually."
Papyrus made a curious sound, or maybe it was just a groan.
"you'd be great at this," he babbled. "you've got such long fingers… i can hardly reach them all." The sound that answered that was definitely a groan.
Maybe Paps would keep his velvety-soft sleeping gloves on.
That gave him an idea. Lurching up into a half sitting position, Sans dragged the pillow out from beneath his skull and stuffed it down into the cradle of his pelvis.
"BROTHER, I—" Papyrus's voice was cracked and ragged through the wall, ready to break if Sans applied just a little pressure.
"yeah bro, me too, me too, fuck." Sans rolled over onto his front, trapping the pillow between himself and the bed and grinding down. Papyrus moaned long and low, and Sans swore he could feel the deep vibrations of the sound like fingers on his spine as he humped pillow and bed. The sharp little pops of pleasure were near constant now, piling up on top of each other in waves of sensation, and he could feel a deeper tension growing in his bones, driving him to desperation.
"SANS, I'M GOING TO—" Papyrus whined.
"yeah, yeah, that's right, come on, paps," Sans panted. He could see it in his mind's eye, Papyrus making the mattress springs creak as he thrust his hips up into the cage of his own big, lovely hands, his powerful cock dripping with spent magic as it throbbed and strained against his grip, so close to the edge. Licks of bright orange magic wisping away for his own ambient magic to eat up. Maybe it was the whipcord tension singing in his own bones that made him demand: "come with me!"
Papyrus grunted, a shocked little burst of sound.
Sans cried back in reply, and a deep, shuddering wave washed over him as he dragged his hips in a torturous circle over the sheets. Fuck, it was too much, too good, but he couldn't stop as waves of clattering shudders racked his bones. He couldn't even pinpoint the individual pulses anymore, dozens going off until that singing tension inside him shattered all at once.
He thought he almost shattered, when every remaining bud he had—there were still so many of them—released all at once, drenching his pillow and himself in slippery blue magic, and the entire galaxy of floating motes around him burst at once into drifting vapour.
It took him a long time to calm down, gasping and rubbing his sweaty face against the soft sheets. After a while, he eased the pillow out from where it had lodged between his overstimulated bones and launched it feebly overboard. It was very much a write-off until he had time to do laundry.
His was just starting to drift off when Papyrus's familiar harsh tones came softly through the muffling wall: "Good Night, Sans."
"night, paps," Sans mumbled, and slept.