Archive of Our Own ^beta

Chapter Text

But Sans’ sleep did not stay peaceful for long, it never did, not even with his daughters calming presence; after several hours of restful sleep his mind once again fell into the void where all his terrors dwelt. Sleep paralysis held him still while his mind screamed in terror. Tears streamed down his face, and he made a small pitiful whine, his bones trembling as he fought the invisible bounds that trapped him, leaving him a slave to his deepest fears. Finding his brother dead, finding his daughter dead, being alone, unwanted, no use to anyone. Being what he was always accused of being, a lazy, good for nothing drunkard who no one cared about and who was better off dead. Someone who just made everyone else’s life more difficult, more pointless. He was in a dark enclosed space, in the wide emptiness of the void with the knowledge of the universe ripping through his mind, tearing his sanity to shreds.

Eventually his mind released him and he sat up with a stifled sob, clutching his hands over his eye sockets as he shuddered, soaked in sweat. His skull felt as though something had stabbed him from inside it; he whined softly in the back of his throat, shivering. He finally managed to slow the bird-fast panicked beating of his soul, his breathing gradually slowing from a rib-hitching gasps. He gradually lowered his hands from his eye sockets, eye lights dim, skull dingy with fear and exhaustion and as his magic reserves, as always, felt drained from the nightmare.

He had expended his magic nearly to the ergs to hold his sanity and soul both together as the void dreams tried to destroy him. He was lucky that he had been able to have such a nice dinner for once, and the sex had also given him an extra magical boost...because otherwise he would have simply passed back out from exhaustion.

Sans fell back limply, staring blankly at the ceiling. He glanced to the side, suddenly horrified that he had hurt his daughter, thrashed or rolled over onto her, smothered her while in thrall of his nightmare. He almost wept with relief when he saw that she was awake, staring at him with wide eyes, lower lip trembling. He reached for her, pulled her to his chest and cooing gently. “mama’s sorry love, sorry, sorry….” Frisk was always easily calmed and she fell back asleep after a couple of minutes. But Sans was not so lucky. And since he was feeling so wide awake now he decided that he might as well do some exploration. He slid out of bed, only then noticing that he was only wearing his blouse and cloak.

He flushed as he remembered what had happened before he’d fallen asleep...the dinner...being teased, being bent over the table...the sex. He clutched his face with an embarrassed moan. Gaster must think he was such a slut! He’d barely met the man and he’d already thrown himself at him! But...if he was honest, it had been the best sex of his life. He pressed his thighs together and moaned again, he wanted more. He wanted to be fucked again, like before, it was so good to be fucked...he froze. Fuck, he was going into heat, wasn’t he...no wonder he was so easily riled, his heat would probably be starting tomorrow or the next day.

He exhaled with annoyance. He would need to find a place to hide, a little bolt hole to wait out his heat. He’d done it before. It was painful, but after a few days, maybe 4-5, he would be back to his much calmer, more secure, dominant self.

And he’d stop throwing himself at Gaster’s feet like a whore.

He took off his cloak, his peasant blouse was long enough that it fell to mid thighs, so he decided that it was long enough to wander the halls in. Of course it did not really do much to hide his breasts, the material was too thin for modesty. But no one would be up to see him anyways. He glanced back over his shoulder at his daughter, but he knew she would stay asleep until he came back; he’d give her a midnight snack then. He turned and tried the doorknob, only now wondering if he had been locked in; but it turned easily beneath his phalanges. He opened the door with a soft sigh of relief and slipped out into the dark hallway, shivering slightly.

Now what?

--

Gaster was in his favorite room in his manor, his lab; he had a writhing cat monster on his table. He was in his element, eye lights shining a dark violet of pure delight (a pair of lab glasses adorned his face, held in place by magic) as he gazed with satisfaction at his newest subject. He had caught this sweet little cat prowling around the back alleys of the Ruins three days ago. He had kept him locked up without food to see how that would affect his digestive track. And now he would cut up his guest to take an up close look.

“Let me go you son of a bitch! I’ll kill you!” the cat screamed furiously, but his voice held more fear than anger, and Gaster just chuckled not in the least moved. The poor desperate little monster was almost crying. It was so beautiful...it was turning him on. He rubbed absently at the bulge in his trousers as he considered his little guest.

“Have you ever heard of the saying ‘curiosity killed the cat?’” He asked and chuckled as he turned away to contemplate his medical cart; the cat began to yell obscenities which he completely ignored. They always seemed to have such foul mouths at this point in his experiments. If he did not enjoy hearing them scream so much he’d have muzzled them all. "It was never said that it was the cat’s curiosity that did the killing,” he purred, turning with a deranged smile, a fresh scalpel in his hand. He began to laugh as he brought the scalpel down on the cat monster and began slicing open its abdomen, blood spurting all over his hands and chest and face.

The cat monster screamed, the sound loud and piercing, it would probably be heard at any hall in the castle the way it echoed. It was music to Gaster’s ears, it made his cock throb with pleasure, already hard enough to press against the front of his pants. Oh, if only his sweet little Sans was here to ride his cock while he worked…

But he would make due with what he had. This cute little cat could provide him all the pleasure he wanted.

Gaster smiled widely as he opened up the cat monster, seeing his lovely organs at work, he set the scalpel down and picked up a probe smiling the whole time “Let’s see what is what shall we? After all, you have such a lovely anatomy...aren’t you curious?” He asked the sobbing, screaming cat that was now begging to be released with hysteria, voice breaking on every other syllable. Gaster licked his teeth and moaned as he continued to play with his new toy.

They would have so much fun together.

--

Sans had started wandering the halls at random, admiring the decor. He could see that everything was gloomy, in disrepair, but underneath that was a lovely golden and crimson splendor with violet touches. The tapestries work works of art, the walls themselves covered in a fine damask wallpaper.The manor was not cluttered with too much finery, but the tapestries, the sporadic paintings on the walls, the magically bound suits of armor that lined the halls, gave the manor a majestic air of masculinity. He approved, not that he thought Gaster would care about his opinion, but next time he saw his host he was going to let him know he liked the paintings. They were landscapes of areas around the Underground, and some things that looked like they might be the surface.

Those he spent a long time staring at.

He was working off the tension which had stiffened his bones during his nightmares and had started to relax when he heard a high shrill scream in the distance; it was the sound of some monster in utter agony. Before he could stop himself he turned and ran in the direction of the cry, not knowing why, but thinking that somehow he could help. He would later blame his newly formed maternal instincts.

The carpets and damasked walls eventually gave way to tiled floors, metal walls; the halls had become cold and industrial. Memories of memories broke like shards of glass in his mind and he flinched, but continued to run, barefoot and shivering. He could not stop now. Someone was in pain, they needed him. The screams kept echoing, shriller and weaker with every repetition. He eventually came to some stairs leading down, the screams had come from there....he hesitated. His instincts screamed at him to not take another step.

Another cry wailed up the stairs. Sans started down.

He could not leave someone to suffer...and that was his downfall.

Gaster barely registered Sans’ magic signature approach, he was too far gone to care. “Ahhhh, yesss...mmmm, oh…yes…” he moaned. The cat’s intestines were unwound and currently his cock was thrusting and wiggling amongst them, leaking his precum all over the red and blue organs. Red was his favorite color…Gaster moaned wantonly, eye lights dilated as he rutted amongst the intestines happily.

“Mmm, red, red red red! So lovely, don’t you agree pretty kitty?” He asked with a low moan before biting into the fresh liver he had just tore out, blood and fluids from the liver dripping down his face, there was a bloody handprint on the top of his skull as he giggled again, “Pretty pretty, so pretty….” He said, watching as the cat gave out its last cry, it stopped moving. Gaster watched and laughed insanely before he started to scream.

Sans stood with his hands clasped over his mouth to stifle his cry of horror, eye sockets wide and vacant. This had to be a dream, a nightmare. A horrible, disgusting, sick nightmare. He had come into the lab just in time to see the poor cat monster’s death throes while Gaster jerked himself off in his entrails. It was absolutely sickening, especially as his frantic mind kept overlaying the moment when Gaster had bent him over the dinner table and fucked him.

“No! No no! You aren’t allowed to stop yet!” Gaster said and began frantically stabbing the dead monster with his scalpel “Wake up! Wake up! We aren’t done! We aren’t done!” He almost sounded like a spoiled child told to put his toys away. He was so close to cumming, how could it die so early?!

Sans stared in horror as Gaster seemed to devolve into a spoiled toddler; he realized that if he did not get out of here, if Gaster caught him, he was as good as dead. It would be him on that table next. He had to leave. Grab Frisk, run. Had to leave. He tried to step back, only for his legs to collapse beneath him and he fell to the ground with a thud. A horrified whimper escaped his throat.

Gaster heard the thud and stopped, arm poised in the air to make another stab. He turned his head, one eye wider than the other as he processed that Sans was there. He was covered in blood and unidentifiable matter. He smiled at Sans the twisted expression nearly split his face in an unnatural manner. “Oh Sans! Did you come to play too?” He asked, climbing off the dead monster that turned to dust right after. His long cock was covered in blood and still wiggling, looking for release as Gaster walked toward Sans. Sans looked so cute, his shirt had ridden up showing his cute little slit still held closed by his magic.

He really liked the look on Sans’ face, it was just like his toys. He must really want to play. He licked his teeth hungrily with a growling moan as he approached his darling little guest, already envisioning how hot and tight his sweet little cunt was. His tentacle cock twitched, wanting Sans’ pussy.

Sans whimpered as Gaster approached him, shoving himself backwards across the floor, missing the door and hitting the wall. He made a terrified whine and kept trying to shove himself back across the floor, his bare feet scrabbling without purchase. His phalanges trembled at his teeth as he tried not to shriek, feeling that if he started he would never be able to stop. And it would just tear him apart. He felt tears beginning to trickle down his cheekbones from his eye sockets.

What scared him the most was the look on Gaster’s face, the morbid delight. The…childish glee. The hungry lust. Gaster was looking at Sans the exact same way he looked at the poor monster-cat on the table. Asking if he wanted to ‘play’…Sans knew he wanted to fuck him, to...cut him up like that cat and fuck whatever was inside...but Sans didn’t have anything inside! He made a strangled sob of fear.

Gaster lunged at Sans who shrieked in terror. He threw himself to the side but was not able to escape the lich’s grasp. He flailed wildly before freezing and crying out with fear when Gaster licked the side of his face as he took him to the dust covered table. Sitting him on it he pushed Sans to lay back, “We're going to have so much fun Sansy! It's just as well the kitty quit playing! You’ll be much more fun won’t you?” He asked petting Sans’ cheek, smearing blood and dust on him, “Plus you are already my favorite color, so much red….” He purred and ripped open Sans’ shirt revealing the luscious ecto body beneath; he got back on the table, his wiggling cock running against Sans’ thigh as Gaster reached for the restraints.

Sans flinched as he was set on the dust covered table, sobbing when the remains of that poor cat monster stuck to his bare bones. He felt like he was going to be ill. Like he would never be clean again, it was so gritty, scratching his bones. He barely heard a word that Gaster was saying, all he knew was that he had to get away. He flinched away from the touch on his cheek, whimpering as he could smell the blood smeared on him, the cat’s blood...he started to hyperventilate, shifting back from Gaster the best he could until the monster tore his shirt open. He could not help the indignant squeal that escaped his mouth as he covered his breasts with his arms and pulled his knees to his chest to hide his nudity. He shivered, gagging with revulsion and fear as he felt Gasters hard, throbbing length curling around his thigh possessively, looking for his pussy.

“gaster- sir...master...please no, please, please don’t do this!” he sobbed.

Gaster couldn’t understand that Sans was being serious, he was in the lab, in the lab everything was fun, it was a game, it wasn’t fun unless they were crying, he knew Sans wanted this. He spread his legs and chained them to each side of the table. He repeated to process with his arms and he paused, gazing at Sans “so beautiful…” He purred scooting up so his cock began pushing into his pussy.

Sans shrieked, crying for real, tugging at the restrains and trying to pull away from the insane monster as best he could. “st-topp!” he wailed, his breasts heaved with his frantic breathing, his soul beating like it would explode. And worst of all, the blood and dust of that poor cat monster was still on Gaster, still on the tentacle-dick that he was pressing against his pussy. He could safely say that he had never been less turned on, but he was unable to dispel his pussy. The gore soaked tentacle began to press into him and he shrieked even shriller than before, writhing frantically. “NOOOO!”

Gaster smiled, but it cracked, seeming to finally be registering that Sans genuinely may not want this. “Are you alright?” He asked cupping his face tenderly, leaning close, blood from his mouth dripping down to splatter onto his face

Sans breath hitched and he looked up at Gaster with dawning relief, eye lights flickering on hopefully. Maybe Gaster was…maybe he just had a split personality in the lab? And…maybe…he would not do such horrible things to Sans? “gaster, sir…please…you…scared me..” he whispered. He tugged at the restraints, glanced down and saw that Gaster was all but sprawled over him, and that they were both naked. He flushed a bright red and looked away. “c-can…you let me go, sir?” he pleaded. He felt Gaster shift his weight off of him slightly, and looked back up hopefully.

Sans saw all sense of recognition leave Gaster’s violet eye lights as they trailed down on his body before landing hungrily on his breasts and all hope of a quick escape fled and he felt as though he were about to cry. Gaster gazed down at him and frowned more “You aren’t enjoying yourself… Is it because I am not doing enough? Must be…” He said softly leaning down and looking at a breast. “You taste delicious,” he said taking a nipple into his mouth and suckling softly. Sans shivered about to call out to be let go when Gaster’s oddly hot mouth latched over his nipple. He threw his head back with a startled mewl, arching up into the lich; he’d never had anyone or anything touch his breasts aside from himself or his daughter. The tug went straight down through his pussy. He had never thought that his nipples were that sensitive.

While he suckled Gaster’s free hand moved around the table beside them, grabbing the scalpel he’d put down after cutting the cat open. He looked up at Sans while still sucking hungrily on his tead, looking deep into his frantically flickering eye lightss “I’ll make it all better don’t worry,” he mumbled around the nipple, he suckled on his breast gently before biting down hard. The scalpel slowly cutting down the ecto flesh of his sternum. Sans panted softly, eye lights dilating as he tried to adjust to the new sensation; when Gaster bit down he rocked his hips up with a violent buck, and he barely felt the sting of the knife. Oh, why did it feel so good?

Gaster felt his soul race, Sans was enjoying it now! He knew he would with proper convincing! He continued to suck and bite on his breasts as he dragged the knife down, carving a neat little line down his toy, his cock thrusting deeper into Sans, forcing its way inward, wanting to be all the way inside, as deep as it could in the tight wet heat.

“aaahhnmmm!” Sans gasped, his voice rising into a keening moan as he arched into Gaster with a wanton roll of his hips and his eye lights rolled back in his skull. He yanked at the restraints with a whimper which trailed off into a squeal as Gaster continued to suckle, and his breast began to secrete his liquid magic, responding to the ministrations. He writhed and whined, rocking his hips as he was filled once again with Gaster’s amazing girth, spearing into his unprepared pussy with an almost violent thrust which had him wailing in pain even as he welcomed it.

Gaster moaned at the delicious liquid magic that began leaking into his mouth. He began thrusting hard, so close to cumming as he carved up his little ward with the scalpel, glad that Sans was finally enjoying their game with him.

Sans gasped shallowly before he began panting with a low moan, crying and sobbing between moans as the pain of his stomach began to compete with the pleasure of his breast being suckled and his pussy ravaged; his body had begun to react to Gaster’s domination and his will, his desire to play with his toy. He was now wet enough that Gaster’s thrusts no longer hurt but instead made him want more, wanted it harder. It felt so good, the mixture of pain and pleasure, his mind had gone hazy, he could not even stop rocking his hips, drooling and sobbing.

Gaster panted, Sans was so tight, too tight… “Ah Sans… You’re squeezing the life from me… We need more room…” He groaned; taking his scalpel and staring down at where his cock pressed up against his skin, he smiled derangedly and and cut into the spot deep into Sans and opened his abdomen up so the tip of his cock wiggled through the hole. “Ah much better….”

Sans shrieked so loudly that his voice broke and his mind was filled with nothing but the desperate need to get away, anywhere, just AWAY! He instinctively pulled his magic about himself like a cocoon and threw himself skipping through the void and back out into another room, landing in a sprawled heap, sobbing and curling up in the fetal position as he began to retch and heave, losing his dinner all over himself.

He was covered in tears and drool, bile and spent magic, the liquid magic leaking from his nipples, arousal from his abused pussy, blood from Gaster’s cock, and blood from his own torso, and his bones were coated with the dust of that poor cat monster…in all, he was utterly wrecked. He found a corner to shove himself into, curled his knees to his chest, and sobbing in pain and fear he tried to figure out where he was. He had had broken bones before, but he’d never formed a body long enough for it to be damaged, and his bleeding stomach hurt, it burned and throbbed, but worst was the hole that Gaster had drilled in his abdomen, it hurt so bad he could almost feel himself blacking out as a self-defense mechanism. He literally could not stop sobbing, and he wished desperately he had never left his room.