It started with little things, as such things do.
Things that Papyrus hardly thought worthy of his notice- it wasn’t as if he expected his brother to be thrilled to be back in the palace. Being excited to face the brother he betrayed would have been strange, even for Sans.
So Papyrus was almost pleased to see that the inside edges of Sans chains had stopped being so shiny, polished by the constant rubbing of his pacing. When that- when Tiffany’s reports claimed that he no longer fidgeted noisily when Papyrus was away, the King was even pleased that Sans was finally becoming used to the new arrangement.
About a month after the first report of this delightful new poise, Sans was even waiting on the bed for Pap’s arrival- as if he had been waiting for him all day. Papyrus was so pleased that he spent more time that he usually would making love to Sans, though this had the unfortunate side effect of making the smaller skeleton keen annoyingly in his pleasure- a problem easily fixed by triggering the silence spell on his collar. Sans evidently enjoyed it a great deal, as his satisfied shudders were so long and violent that they cost Papyrus even more precious hours of sleep.
As time went on Papyrus noticed Sans rarely spoke except when spoke to, an improvement he should have thought to arrange, as he found it as or more satisfying in his bed as he did in his throne room.
It did seem an unnecessary waste of his time to suppress the silence geis when Sans didn’t even particularly want to speak though, so Papyrus stopped doing it, except occasionally when he wanted to hear a response- like whipping. Whipping was so much more satisfying when he could hear Sans cry out. Or so he had thought till he accidentally left it on for one session- and discovered that the desperate look in Sans’ eyes as he silently begged Papyrus to stop (or for more. He wouldn’t put it past the horny little shit) was the most arousing thing he had ever seen on his lover’s features.
He particularly liked that look as he raked his teeth up Sans’ arm as he fucked him to ecstasy, inwardly resolving to create that expression as much as he could.
And the first time Sans hadn’t jumped when he entered the room, stayed sitting with his eyes down respectfully, Papyrus had been overjoyed. Finally, his obnoxiously loud brother was truly becoming the demure queen Papyrus deserved. This confirmation of Sans inherent suitableness to his station led to Papyrus magnanimously focusing on Sans pleasure for the first round.
Papyrus couldn’t see Sans’ face nor hear his habitually silenced moans as he nipped and sucked at his brother’s simulated flesh, but if the flinching of his leg bones and the spasms of his entrance were anything to judge by, he was thoroughly enjoying himself.
Papyrus only began to be displeased when Sans started sleeping through the day. He dismissed Tiffany, as her reports, remarkably well done as they had been, continued to report the same thing every day- “no sound indicating any major activity from the queen.” Though he had somewhat expected it, Sans relapse into laziness disappointed him. He had still hoped to perhaps train sans to be useful for something besides his pleasure- perhaps being his personal scribe, though that would take a great deal of work, as Sans penmanship had always looked unprofessional.
Even more annoyingly, Sans lethargy infected the bedroom as well. His small hands no longer clutched Papyrus’ shoulders, instead laying taut at his side as his body shifted from the contact of their bodies or folding passionately in front of his teeth as though to hold back cries already silenced by his restraints.
The way his eyes focused on Papyrus though- his queen’s face already pointed to the door, expecting him; the way his eyelids lifting from the half closed position they seemed to have by default when he returned, before Sans could reconquer his expression, was beautiful and it never failed to make Papyrus’ chest warm, strengthening his resolve that no one may see Sans like this.
That was the image he was anxious to see as the skeletal king stomped silently down the hall to his chambers. He imagined his lover sprawled over their bed, a look of recognition on his face, beckoning to him in invitation as the magic wards on the hall read his magic and his motions, recognizing him as Safe for Sans. How thoroughly he was protected was a secret Sans didn’t need to know.
When he finally reached the ornate wooden doors, he opened them noisily, an occasional indulgence to see Sans surprised face- so cute it was nearly obscene, a sight for Papyrus alone.
Indeed Sans was on the bed, in a position very similar to the last Papyrus had seen him in when he had left the chamber that morning. He had his back to the door, thee fine bones of his arms laying in front of him in a way that Papyrus wouldn’t be able to see if his lover were clothed.
And he hadn’t even twitched.
Papyrus was so caught off guard he hesitated a moment. It had been months since he last tried to get that reaction from Sans, and it wasn’t as though Sans could be expecting anyone else, perhaps he was no longer startled by loud entrances.
Oh, wait- he’s asleep. Obviously.
Yet, Papyrus couldn’t shake the feeling that something was very, very wrong. He felt the tension in his shoulders as he slowly, almost cautiously began crossing the rather large bedchamber. His finger twitched as though to summon a bone attack, and yet he couldn’t perceive any threat. None of the wards to mark unauthorized passage were triggered, nor were any of the traps in the hall. The window was bricked as he had left it and the wardrobe’s external locking mechanism was engaged. Then he realized:
Sans wasn’t breathing.
Papyrus had studied medicine in the two year Sans was missing, one of many practices he had mastered to distract himself from his brother’s “abduction.” He had intentionally focused on medicine for monsters without flesh, justifying himself that if the palace physician could be tricked by such a simple ruse, then they represented a serious security breach. Consequently, Papyrus was probably the best healer in the entire underground.
In the process he had learned that while some monsters needed to breath in some way to maintain their bodies, fleshless monsters merely needed to maintain constant motion to regulate their magic levels. In a flesh and blood monster, magic could mimic chemical compounds to move, which was a very stable state for magic. In fleshless monsters, however, the magic had to forge connections that acted like ligaments and muscles without actually forming them, which caused painful or unsafe magic blockage in the joints, but could be safely alleviated by constant minor movements.
If left alone, these buildups can destabilize the monster’s form, usually resulting in it collapsing or spontaneously losing limbs. Fortunately, there were only two known cases when this motion stops. The first is if the monster was near to fatally starved.
The second was if they were in the process of falling down.
Papyrus lunged for Sans- he had to get him moving, if he could restore circulation, maybe he could save him!
He scooped Sans up under his armpits, briefly distracted by how absurdly light his brother was, he lifted and lowered his younger brother in an absurd limp version of squats. He looked into Sans’ eyes and only saw the vacant black depths of the inside of his skull. He had never understood why so many monster’s found that visage disturbing- but now it was clear. There was a cool tranquility, an aloof perception to the empty eyes that shook Papyrus to his core.
He looked into those black eyes and death looked back.
Papyrus’ panic fired his voice into a smooth plea, unlike and yet similar to every syllable he had ever uttered:
“Sans. Wake up. You have to wake up right now. Now.”
It seemed to do nothing. And yet the smallest of grey specs coalesced in Sans’ eyes, though he remained limp in his brother’s grip. His mouth fell open and his features twisted into an agonized expression- as though he couldn’t breathe, his head falling back to reveal the ridiculous silver collar on his neck.
Papyrus rent the enchanted metal from his brother’s drooping limbs in seconds, it’s strength no match for his desperation, and laid his brother back to move his slack arms for him.
“Sans. You need to tell me. What caused this Sans. Tell me. Sans.”
A look of abject sorrow crossed the small skeleton’s face, and Papyrus was reminded of a time that felt an eternity away, a moment he had examine countless times to discern how he should have seen Sans’ treachery coming- when he made a simple compromise with his brother.
He remembered Sans words.
‘don't you get it, boss? you're killing me! I can't handle this fucking isolation anymore! i need fresh air! I need people to talk to who'll be there to talk to again the next fucking day! why do you hate me so much?!’
And the faded eyelights vanished.
And Papyrus leaned down to kiss his brother tenderly, and with all the urgency he could muster. “Sans, Sans, no, you are so precious to me. You can’t leave. Your my gem. You’re too beautiful to stand. Please, please, stay. I’ll get you handmaidens- more than you ever had before- that last one- Tiffany- she’s still alive. You can have her back. You’ll never have to be collared again. And you can leave the room. You can even go back to the ruins. Just please don’t go. Please, Sans. Anything but that. Sans. Please. Please wake up, Lazybones. Sans. ”
As he spoke he caressed his brother. Memories of his brother writhing under his touch and moaning as he leaned into his brother’s touch presented themselves to him, and Papyrus recreated them exactly. He stroked his brother’s cheek in the way that would make him sigh. He nibbled his neck in the way that would make him gasp. He held Sans hip in the way that would make him beg.
All these touches belonged to an older time; when he was in the guard and they lived surrounded by the fine powder of Snowdin. A time when Sans was happy.
But Sans was silent and still.
Papyrus felt as the bone beneath his hands grew porous, as if flaked off beneath his teeth. And he stilled, remembering.
Sans' face splitting into a beatific smile, he nuzzled into Papyrus' chest, threw his arms around him. The larger of the two had chuckled. "I love you."
‘thank you, thank you... i love you, papyrus…’
“I love you…” Papyrus whispered.