How, they couldn't help but wonder to themselves through their initial panic, did they end up in a situation like this?
Well, it had started because Undyne and Alphys had decided that all their friends should have a get-together anime marathon, since all of the group had been busy with surface things and thus hadn't seen each other often. Between Toriel's schooling career, Asgore's gardening and desperate attempts to win his ex-wife back, Undyne's personal trainer job, Alphys' job in the labs, Papyrus' constant spaghetti-making, Frisk's ambassador business and fights for monster rights, and Sans' sheer laziness, the group had hardly been able to see one another in nearly two months. Alphys and Undyne -mainly Undyne- decided to schedule a day where everyone was required to take off so they could all get together and catch up over some nice episodes of Hetalia. ("It's actually about human history!") Papyrus, of course, didn't come, grumbling something about babies and Mettaton, but everyone else was more than happy to attend and meet up with their favourite fish and dino couple.
Toriel and Frisk were the first to show up, a butterscotch-cinnamon pie in hand. This, ultimately, wasn't a surprise considering the fact that the two, well, lived together. Turned out Frisk was an orphan. Their mother died in labour, while their father passed of alcohol poisoning shortly before Frisk fell down the infamous Mt. Ebott, and since there were no other relatives Frisk knew of, Toriel quickly adopted the human as her own.
Asgore came shortly after the duo, looking flustered as anything, golden eyes laced with worry continuously darting to Toriel. The female boss monster had kept a stone-cold face, either ignoring the ex-king entirely, or shooting daggers in his direction.
Sans, unsurprisingly, arrived last, not even entering the house. The only sign of his arrival was a quick knock on the front door of the fish warrior's house.
"Sans, I swear-"
"Who's there?" Toriel cut Undyne off, leaving the fish woman to sigh, pinching the bridge of her nonexistent nose with a webbed hand.
"iva"
"Iva who?" the goat woman chuckled. She'd heard this one before, but still enjoyed it nonetheless. It was the same with all of the short skeleton's jokes.
"iva got a sore hand from knocking. do a vertebro a favour and lemme in?" Sans finished with a wink, despite the fact that no one could see him. This sent Toriel howling with laughter, while Asgore simply stared, longing hanging heavy in his soft eyes.
"Sans you can let YOURSELF IN! You don't need to pull this CRAP every FUCKING TIME you come over!" Undyne yelled from her seat on the couch, earning a sharp gasp and harsh glare from Toriel. Undyne simply shrugged in response before absentmindedly reaching for the bowl of chips on the counter-
Only to have Sans in her face with the bowl not even a second later, noisily shoving a handful into his mouth.
"yeesh. no needta be so sternum." he managed to say between bites, giving a shit-eating grin at Undyne's glowering.
"Yaknow what? WHATEVER! This shouldn't even surprise me anymore! Alph, hand me the remote wouldja? I need to put the anime on before I go crazy." exclaimed the fish, nodding a curt thanks as her girlfriend handed her the remote.
Sans had only laughed in response before he was in the kitchen, reaching into the fridge. Grabbing a a bottle of ketchup from the pair's fridge, he had been about to dump it on the chips, when Undyne pointed to a cabinet without looking, and interrupted his action.
"We've got some ketchup-flavoured chips in there, Sans, so don't go tainting our good chips."
Frisk crinkled their nose. Ketchup potato chips sounded so wrong! But really good, too. Maybe they'd steal some from Sans.
With his newfound love of ketchup potato chips, Sans settled into the large couch with everyone else (with the exception of Asgore, as he was much to large to fit on the couch), as the anime's opening sequence began.
Despite the fact that Toriel often openly gaped at the lewd humor in the anime, covering the human's ears more often than they would have liked, the whole experience was pleasurable to Frisk, and a good way for Sans to temporarily forget his troubles and plagues. Just talking could be surprisingly relaxing. About foods, about jobs, about work, about sleep...
That was, until a loud, frantic banging on the front door could be heard.
Everyone in the room stared at each other, utterly perplexed expressions gracing all of their features. They hadn't the faintest idea as to who could be at the door, since Papyrus hated anime, and no one else had been invited. No one dared to move in fear as to who, or what, could be knocking at the door, each occupant of the room daring the others to stand up and answer it with their silent gaze. Eventually, Undyne gave in and silently sprinted over to the door, her clawed hand only inches away from the handle, before it was kicked open with an unbelievable amount of force, causing Undyne to leap back to avoid the door.
"HEY! EVERYONE! LOOK AT US!" an odd, and yet familiar, voice chimed. It had robotic undertones, in sort of an echo, that reminded Frisk of Mettaton.
And, much to Frisk's surprise, there stood an odd robot-looking monster, with dramatic white, pink, and black armour, complete with a pink bandanna. The robot's structure was odd, too, and rather than having the arms reminiscent of noodles, they appeared to have more of a bon-type structure, topped off with pink gloves. The midsection was thin, almost as much so as the arms, but encased in a semi-translucent pink box of some kind, protecting the midsection.
"Woah-ho-ho, look at you two! Finally figure out how to fuse?" Fusion. Fusion? Could monsters fuse? Frisk hadn't known that.
"YES! IT'S AMAZING! IT'S WONDERFUL! IT'S ALMOST AS GREAT AS ME!" the robot exclaimed, whilst striking a dramatic yet heroic pose.
"D-did you really f-fuse?! W-with Mettaton?! H-how did- How i-is that even possible?! U-unless Mettaton's fully c-corporal state allows f-fusion...!" Alphys hadn't wasted time in running around and examining the fusion, shock filling her features.
"Oh, how wonderful!" was Toriel's only input, while clasping her large paws together.
Frisk, however, was still utterly, hopelessly confused. They looked to their adoptive goat mother for an answer, but she was staring at the fusion with a wistful expression on her fluffy face. Asgore was looking at the floor, and Undyne and Alphys were berating the fusion with questions, which left Frisk going to Sans for an answer.
Sans' eye socket were completely black, staring at the fusion with a neutral expression, though they could have sworn a look of hurt flashed across his face for a split second.
"heh. w-wow, paps. this is uh..." Sans hadn't known what to say. "well, gotta bolt."
And with that, he was gone.
Wait. Paps. Mettaton had fused with Papyrus? Wow.
The fusion, however, looked suddenly perturbed, a gloved hand grabbing their face and roots of the black hair, to Frisk's surprise. He wasn't angered in the slightest by Sans' pun, which was perhaps the strangest thing about the whole situation.
"May I... Sit for a moment?" the fusion's voice was suddenly low. Almost remorseful. It was odd, considering neither Papyrus nor Mettaton could ever really keep their voice down, and Alphys gave the fusion a quick nod, before pulling a chair from the dining room that the couple hardly ever used.
"When I- err... Well," the fusion cut himself off, unsure of how to address his half, "when Papyrus and Sans were younger, they promised that their first fusion would be with each other. Now, that wouldn't have been a problem... But Sans... Couldn't really get the hang of fusion. At all." he sighed, looking so full of regret. It was obvious Papyrus was the one who was mainly in control at this point, but Mettaton was able to use some self-control to keep the fusion's voice low.
"Why?"
All eyes turned to Frisk, who hadn't spoken at all since the whole ordeal started.
"Oh! Right, the lil punk doesn't know about fusion, huh?" Undyne realised, looking at Frisk with a wide grin.
"Ah! Well, my child, when two monsters become close, whether as friends, family, or," Toriel glared at Asgore, "as soulmates, they can combine their magical beings into one, temporarily of course! Humans cannot do this because they are not magic-based! It is the same magic used for... Making children, but rather than making a new soul, monsters simply combine into one. And it usually happens while the two monsters are singing or dancing together, as the two are linked usually with raw emotion. Monsters cannot fuse when they're panicked, if they don't trust each other, or for various other reasons. Monsters don't fuse too often because of the fact that it is very taxing and will take a lot of magic." the goat monster finally concluded, smiling. It's no wonder she was a teacher.
"YES. AND THAT ONE BEING HAS ITS OWN MIND! LIKE ME! AND IT HAS THE COMBINED PERSONALITIES OF BOTH. THINK OF THE TWO MONSTERS THAT MAKE THE FUSION LIKE CO-PILOTS." the fusion chimed in, his voice returning to the loud, exuberant tone it was before.
"Though... Why Sans cannot fuse... Maybe his magic is not strong enough? He does only have but one HP, does he not?" Toriel proposed, earning a sullen look and hesitant nod from the fusion.
"U-um, so w-what's your name, th-then?" Alphys questioned, obviously trying to shift to a more comfortable topic. It seemingly worked, as the fusion's posture straightened immediately.
"WE- THEY- I WAS THINKING PAPYTON! YOU KNOW, AN AWESOME FUSION NAME FOR AN AWESOME FUSION?" he smiled hopefully. After a second, his eye sockets lit up -literally- with excitement. "HEY! YOU TWO SHOULD FUSE! WE COULD HAVE A FUSION PARTY! DON'T YOU WUSS OUT, BECAUSE I KNOW YOU WANT TO!" he grinned, eyeing the two mischievously.
"That could be fun! HEY ALPH, whaddya say?!" Undyne grinned her signature grin at Alphys, whose face was a bright red.
"L-let's do it!" Alphys exclaimed, nervously smiling at Undyne, who responded by picking her girlfriend up and spinning her around. Their bodies started to glow and morph, before a curvy green monster with red fins was standing in front of Frisk.
"Heheh! Been a while!" the newly-fused monster exclaimed while stretching.
Frisk stared in awe for a moment, before bounding over to Toriel.
"'M gonna look for Sans..." Frisk had whispered to their adoptive mother, earning a cautious look and a soft nod.
"Alright. I trust you, my child. But do be careful, please?" Toriel responded, proceeding to pull the human into the warm, fluffy embrace that they loved oh-so much. Once the hug ended, the boss monster pressed a kiss into their forehead and sent them on their way.
Of course, it didn't take too long for Frisk to find Sans. Like they had suspected, the short skeleton had holed himself up into his room. Luckily, since the skelebros moved into their new house, the younger of the two skeletons had given Frisk a key that would unlock Sans' room.
"Sans...?" Frisk was greeted by darkness. That was expected, if Frisk was going to be entirely honest.
"a-ah! hey kiddo..." Sans turned on his light, and sat up from his mattress to greet the human.
"Sans... Everyone is worried about you. Mom, Undyne, Alphys-"
"papyton?" Sans cut Frisk off with a scoff and a sideways glare. He really didn't need this now.
"Yeah, Sans, he's worried about you, too... If... If you wanna fuse... Why don't you fuse with Mom?" Frisk questioned with wide eyes.
"wh-what? fuse with someone else's soulmate? you must be kidding! i mean-" Sans had cut himself off, and started thinking it through. He and Tori were good friends, and, realistically, they could definitely fuse. Now, his ability to fuse on the other hand...
Sans mumbled something inaudible to Frisk.
"What was that?" they asked, a smirk growing on their face.
Sans didn't meet their eyes, but his eye sockets were dark and his cheekbones were tinted a light cyan as he mumbled again, the uttering being just a bit louder than the last.
"You're gonna have to speak up, Sans!"
"i... can't dance. i can't sing. so i can't fuse, kid." Sans finally admitted, meeting their gaze shyly. God, he thought must have looked stupid. They were probably gonna laugh or something, he had thought.
"Then practice with me. Monsters and humans can't fuse anyway." Mistake 1. Frisk's proposal had been so innocent, and Sans had been so eager to take it.
"alright, kiddo." the short skeleton sighed, earning an enthusiastic squeal from Frisk.
"And another thing, I'm not a kid anymore, Sans!" they huffed, poking a finger to the skeleton's chest. They did like his nicknames for them a lot, but they just weren't a child anymore!
"oh yeah? you'll always be a kid to me, shortstuff."
"I'm taller than you, Sans! Besides, I bet you're not that much older than me! How old are you?"
"that i don't know, kid. all the," he gulped, "ah... well, my mind's not great with memories anymore so uh heh. anyways um..."
'So anything to do with time is a touchy subject for Sans,' Frisk figured. They stored that away for later use, but they knew that they had more pressing matters on their hands.
"Um... So, Sans, do you know anything about dancing...? Or singing...? At all?"
"i wish, kid."
"Then... Once the music starts...Take my hand and follow my lead." Frisk gave Sans a gentle smile. They themselves hadn't actually known much about dancing, but they loved to just turn on music and glide around the room, letting the music take them.
"alright, kid, whatever you say. i trust ya." Mistake 2.
Frisk had quickly found a song, a beautiful instrumental that started out slow and soft, but picked up and became exciting, without losing the quality. The human loved the song.
The music started and Frisk put their hand out, and Sans eyed it cautiously, like it might burn him to the touch, before hesitantly sighing and slowly reaching out to it. Frisk smiled in return, and began to move, signaling Sans to do the same. Sans began to copy Frisk's movements, albeit clumsily, with a newfound confidence. As the song droned on, Sans' movements became less and less clumsy, and more and more confident and fluid, as Frisk's movements sped up and became more excitable. By the end, both had been mindlessly dancing around the room together, when Frisk stumbled and began to fall. Frisk was ready to feel pain shoot through their leg, but they hadn't. When they'd looked up, Sans had caught them, and was now smiling, for real, and began to laugh. Frisk joined in as well, looking up at Sans, eyes sparkling with laughter, as a warm feeling blossomed into their chest and quickly overtook their whole body, and their mind fell into an abyss of white.
When they regained consciousness, something felt off. Very off. But, oddly, right. Like this was normal. They looked down at their sock-clad feet. Scandalous. Wait... They... Weren't wearing socks earlier, were they? Yes they were! They came in wearing boots, right? No they didn't... Er... Yes... They did.
They looked ahead and found a pair of winter boots laying on the floor in front of them. Those were theirs, they had deduced. They had never seen them before, but they just knew they were theirs. They absentmindedly slipped them on, catching a glimpse of their hands in the process.
They were white as the snow, and while one resembled a human hand, the other was a tight, skeletal hand. At the sight of both they sent themselves back into the wall, unsure of which hand to be more shocked about. That's when they pulled themselves up and ran to the nearest bathroom. They had a sneaking suspicion as to what was going on, but part of them hoped to the gods above that it wasn't that.
And their prayers went unanswered.
Staring back in the mirror of the bathroom was what appeared to be an adult human with pure white skin, messy brown hair... And no eyes. Black voids stared back, large, glowing white orbs swimming in the abyss of black. Morbid curiosity brought the human hand up to the eye socket, about to reach into it, when a voice sounded through their head, and the skeletal hand grabbed the other and brought it down.
'let's not do that.'
Sans' voice. That was Sans' voice...! Where was Frisk's voice?
Wait what?
Right. Right. They had more pressing matters. They continued to stare at their reflection, completely dumbfounded. Their outfit was unfamiliar, as well. It was a blue sweater with a hood and a single pocket in the middle, black pants-almost-leggings, and brown, fluffy snow boots. Gods above did they look weird. They liked it, though. It was comfy.
"so... this... is fusion?" their own voice surprised them. It was a tad lower and more mature than what they were used to, if they were to be honest. Though, Sans was the one talking through the fusion, so the voice sounded a little awkward as well.
"It's... Great! Strange, yeah... But energizing! And new...! Heh..." the fusion spoke now, loving the feeling. Both parties did love the feeling of fusion, and since it was the first fusion for both, it was exciting. Except... Now the dread took over.
"Ohh shit shit shit what are we- they- you- What am I gonna do?!" They practically screamed, pacing around the room. "We gotta unfuse! You gotta unfuse right now!"
Frisk tried their hardest from inside the fusion to break free, but they simply couldn't. It was futile. Gods, were they stuck like this?! No. No that... Sans didn't fully want to unfuse. And... Neither did Frisk. A small part of each of them wanted to stay fused. Sans wanted to show Papyrus that he could fuse in the first place. But the anxiety masked their wishes to stay fused.
"W-we- I- Let's head over to Alphys and Undyne's place. Tori and Asgore might know what to do."
And in that instance, Sans took over the fusion, and what could only be described as magic bubbled up within the fusion, and they found themselves outside the house of the couple, where Alphyne and Papyton's voices could be heard even from the outside. They inhaled deeply before knocking on the door with their skeletal hand.
"SANS DON'T YOU DARE." Papyton's voice came from inside, obviously knowing what was going to happen next. Both Papyrus and Mettaton hated Sans' jokes, so, of course they scolded him, but they blissfully unaware of who it actually was at the door.
A mumbling came from inside, and the shuffling of paws against carpet could be heard. "Sans, perhaps it is not the best idea to tell jokes now. Why don't you and Frisk come inside and we can sit down and talk. They are with you, are they not?"
"That's one way to put it. Tor- Mom you might wanna sit down." the fusion said quietly in almost-Frisk's voice. They really didn't want anything bad to happen because they just burst in! After all, hadn't Toriel said that humans couldn't fuse? Ha, how wrong that was.
"O-oh. Alright, my child," there was the sound of scuffling paws again, and Toriel's now-distant voice called out, "I am sitting!"
The skeletal fusion took in another inhale of crisp air before pushing the door open and stepping inside the house.
"SANS? HUMAN?"
"F-frisk?! NO WAY!"
Both of the other fusions seemed absolutely dumbfounded, but smiled excitedly nonetheless.
"THIS IS AMAZING! Almost as amazing as me, but not quite. STILL THIS IS GREAT! SANS, FRISK... SARIS? HOW DID YOU DO THIS?" Papyton seemed beyond excited, probably because Papyrus was ecstatic for his brother, and Mettaton for the human.
"I uh... Don't know. Kinda why I'm here, tibia honest."
"FRISK, HOW COULD YOU LET THIS HAPPEN?" Papyton angrily groaned at the overused pun.
"Hey, stop ribbing me for it! Frisk loves Sans' puns!" the newly-dubbed Saris grinned.
Alphyne seemed even more excited about the fusion than Papyton. "A human an monster fusion? This is crazy! H-how is it possible I mean... Just... How?! Can d-determination can fuse like magic?" Alphys spoke through the fusion, obviously out of her mind with ideas and theories.
"Doc, y'mind not making us- me into a determination experiment?" Saris suddenly spoke up, Sans' drawl prominent in every syllable. Both Sans and Frisk had been all-too-familiar with the amalgamates, who, the fusion just now realized, were fusions caused by Determination. Could that be more of a reason as to why they couldn't unfuse, more so than their subconscious will against it? Could the determination from the human, along with Sans' own determination from his experiments, be holding them together in a permafused state? Gods above they hoped not.
"R-right umm..." Alphyne suddenly looked both scared and nervous, eyeing Saris but avoiding looking their way.
"My child, Sans," Toriel finally spoke, using a cautious, low tone, "Saris, was it? I trust you were not doing anything-"
Saris' face suddenly turned a bright purple, and seemed to absolutely glow. Asgore, on the other hand, seemed to have the most menacing expression the room's occupants had ever seen. After all, Frisk saw Asgore as their father, a role of which Asgore accepted without complaint. Seeing this, Saris's faced seemed to, somehow, grow whiter for a split second, before turning and even more brilliant purple than before as they felt their sins crawling up their back.
"N-NO! It wasn't anything like that! N-not at all! W-we- THEY were just dancing! And then Frisk fell and Sans caught them and-" Neither knew, well, anything about fusion, and since Toriel and Asgore clearly knew the most, considering Asriel, they had to clear up any potential misunderstandings. Especially ones that dealt with anything... Intimate. And if Toriel and Asgore thought they were doing things like that... Well... This whole fusion thing was gonna be a long experience. And Saris felt like they were in for a bad time.
A/N-
so i think i'm obligated to say that this is my first fanfic?
also, i don't ship papyton, but i don't dislike the ship. it doesn't even have to be seen as a ship, but as a friendship in this story and i plan to keep it up for interpretation
what i do ship is Sans x Frisk, but i'm not sure if i should put it into this story. if i did, obviously, Frisk is older and probably around 16-20, while Sans' age would remain ambiguous, but probably wouldn't be over 29.
And if you couldn't tell, i do plan to continue this with some smaller stories about their life and dealing with being a fusion, and, maybe, Sans and Frisk dealing with being unfused after being fused for so long
so lemme know what you think, and if i should ship Sans and Frisk in the story!