Chapter Text
“Wait, can you just give me an overview of what I need to do?” Sans said into the phone, looking lost and beginning to get irritated.
“S-so, uh, you… just go through all his external features, and, um… if everything is alright, you go and clear the data cache on those, then y-you power him down and run internal checks and um… clear out the oil grill if it needs it. You’ll know if it does. That PDF if just um… basic instructions on how to t-test out everything.”
“Right.” He scrolled down the PDF. “Okay, buttons, vents, eyes… wait, do I not need to check anything about the dial?”
He heard Alphys let out a squeak of surprise. “Th-the what?” she tried to cover.
“The dial. On his chest. The giant-ass dial.” Silence. “What’s that dial even for?”
He heard her gulp loudly before she began explaining, clearly trying to keep her voice even. “So, when Mettaton was first being built, he wasn’t so much a… performance piece of tech. He was more intended for weapons defense. Like… like the ultimate soldier.”
“Yeah, okay.” He wasn’t sure where this was going.
“And, um, that d-d-dial…” She paused. “It was supposed to be used to… counter any pain he felt while in battle. It helps generate a feeling of like… somewhat ticklish numbness that would wash out the pain and make it less distracting until he could be repaired again. Only it, um… Didn’t… work how it was supposed to. It generated a slightly less… estimated effect.”
Sans processed this for a few seconds. “Alphys, either you’re telling me that you gave him an automatic loopy switch—which I’m pretty sure is the less likely option of the two—“ He could practically hear her sweating. “—or you gave him a happy button.”
“It was an accident, and it would have taken months to remove again—“
“Alphys, jesus.”
“Just don’t touch it, okay?” she cut in before hanging up abruptly, Sans now more educated in a way he wasn’t entirely sure he needed. Being Mettaton’s agent kept him busy enough, and if Alphys ever came back out of hiding again she would be the one doing this, but instead it was tacked onto his endless list of new responsibilities. Apparently every two months he was supposed to run a systems check like this, more often if he started acting buggy. They really couldn’t put it off any longer, so Sans had decided to help him out with it. And now he was curious. Which was a problem. More for Mettaton than himself, though.
“But it’s so annoying…” Mettaton whined, putting on his best agonized expression. Sans was unimpressed.
“Yeah, well so is powering down randomly on stage because one of your circuits is running too much power on accident. If your battery gets drained because you’re stubborn, I won’t be happy.”
“But Sans…” He whined again dramatically, swinging his legs up onto the table so he could lay backwards, lounging and pouting like his problems were truly the most agonizing in the entire universe. “Every two months is dumb! Once or twice a year is more than enough caution!”
“Until it isn’t,” Sans replied evenly. “Just calm down and let me go through the list, glambot.” He looked down at the physical piece of paper with small, summarized versions of what he needed to do written down for his convenience. He started with Mettaton’s feet, just checking to see if they creaked, same with his knees and elbows, and finally his neck. Already Mettaton looked increasingly bored.
“Sans, I do this every week the day before shows start up again,” he said impatiently.
“I know,” Sans said, which he did, because it was technically his job to know now.
He looked at the list. Check optics and jaw. He was about a foot too short to be eye-to-eye with Mettaton, and the low table that Mettaton decided was suitable for his checkup wasn’t wide enough for them both to sit on. Suddenly, Sans felt the inkling of a plan that he had going begin to grow. He might as well get a head start.
Without further ado, he swung himself up onto the table as well and straddled Mettaton, whose eyes widened in surprise (every time Sans could crack his composure, it was interesting to see). “Sans, what are you—“
“Hold still,” he said commandingly, and to his surprise Mettaton did just that, closing his mouth after a moment as Sans combed his hair from his face and began looking closely at him. Sans pretended he didn’t notice how Mettaton’s face was gradually warming up. He stared directly into Mettaton’s eyes for several moments (wow, that’s a nice color). He waited for several long, silent seconds, looking over his face carefully, until Mettaton seemed ready to speak again. He spoke up before the robot got the chance. “Alright, your jaw looks like it’s still in line, and your eyes seem to be blinking properly. Can you take in a deep breath through your nose?”
He did so, and in the part of Sans’s mind that wasn’t distracted by thinking this was hilarious, he registered that there was no whistle or hollow sound. “Good.” However, he only moved backwards slightly, not quite off his legs, but just above his knees. “Can you put your hands on your hips for me real quick?”
He waited for Mettaton to do so before he leaned down and forward (Mettaton’s breath hitched, and Sans was pleased with himself), looking back down at the paper briefly before he ran his hands up Mettaton’s arms (Mettaton swallowed hard and Sans wasn’t sure how he wasn’t already grinning like a maniac). He reached the underside of the spiked shoulder pads, his bony fingers finding the seam and running along it slowly, methodically, and Mettaton was definitely about to lose his cool.
“Alright, it seams to be fine.” Mettaton slapped his arm, and now he really was grinning. “Next up… hmm…” Sans frowned at the paper, his acting impeccable. “You gotta do this part for me. Can you open up your soul chamber, Metta?”
And Mettaton was completely still for one, two, three long seconds before his hand slowly moved to the glass-encased box. There was a soft buzz and a hiss as compressed air was released, the box popping off cleanly. Exactly how it was supposed to. Sans nicked the box from his hands and laid it to one side, out of the way. Then, after staring at the paper for several seconds, he picked up the small, oddly gelatinous heart from its container.
Mettaton seemed to stiffen, eyes staring directly behind Sans into the open air. Sans forced down his sly smirk and did what was apparently the most important part of the checkup. He ran his hand over the substance that almost seemed to want to slip between his fingers, while being entirely rigid. He found no abnormalities, lumps, folds, or places that it was crumbling away, and so that was done. Mettaton still refused to look Sans in the eye, and now the electric humming constantly present when Mettaton entered a room was more than a soft background noise, the volume climbing until it was noticeable. Sans noted how his body temperature seemed to have decreased, and he realized the sound must be his internal fans whirring away.
He paused for a moment, before once, experimentally, squeezing the heart.
Mettaton clenched his teeth to keep silent, eyes squinting shut in a way that was definitely not in pain. He seemed to hold his breath for several moments before exhaling shakily. His eyes opened back up and—wow his pupils were dilated now and positively glaring at him, Sans felt a great sense of accomplishment that even with these little minute movements, Mettaton seemed ready to crack any minute.
And so he placed the heart back in the box (notably not closing it) and wiped his hands (which were strangely damp now, how on earth did that happen, he wondered) off on the front of his own sweatshirt (Mettaton’s eyes had snapped back up to the ceiling when he did that, biting his tongue, no doubt). Then, he picked back up the paper again, acting as if he didn’t notice how Mettaton shifted ever so slightly, taking a few deep breaths to steady himself. Sans too was beginning to feel warmer, sweat collecting on his brow ever so slightly. He acted like he was reading the paper (which mentioned exactly none of what he was about to do), and he then, as if he didn’t know the gravity his actions held, reached forward and placed his hand on the dial.
Mettaton’s hand was on his wrist before he could even blink, and the diva was staring him down, and Sans stared right back, an eyebrow raised. “Sans,” Mettaton said evenly with great effort. “Don’t touch that.”
“Says right here that I need to make sure none of your buttons or dials are sticking,” Sans said, tapping the paper with one hand (don’t call his bluff don’t call his bluff don’t call his bluff). “Doc’s orders, robot, sorry.”
Mettaton was clearly looking for a way out of this situation, any excuse to be able to not have Sans touch that one specific dial, and Sans certainly didn’t wait long enough to hear it. Instead he wrenched his hand just to the side (five settings, oh boy, the decisions), and turned it on to the first notch.
Instant effect. Mettaton’s shoulders tensed, and his mouth fell open slightly, eyes fluttering closed. “Nng…” he hummed in the back of his throat. Sans turned down the dial again calmly, feigning concern.
“You okay?” he asked innocently, and Mettaton was clearly trying to play it cool, steadying his breathing.
“Just… hurry up already,” Mettaton said.
He shrugged nonchalantly and turned up the dial again. This time, Mettaton bit down on his knuckle, expression firm with resolve, absolutely not giving in to this, not that easily. Well, that just wouldn’t do, Sans thought, and he flicked the dial up another setting to number two.
Now Mettaton’s back arched and a sound that could only be described as a mewl left his lips, and Sans realized just a little too late that now he was grinning, and Mettaton’s face was practically burning with shame as he stared in shock at the short skeleton.
“W-wait, you knew!? Why, you little—“ Sans was almost positive that Mettaton was about to clock him in the jaw, so instead of facing that, he decisively turned up the knob once more. Instead of punching him, now Mettaton was falling back onto his elbows, eyes fluttering shut again as he gasped, and Sans felt his knees beginning to shake underneath him. The robot groaned softly, but it came out fractured, the metallic equivalent of a voice crack making it jump up between octaves and skip like a broken record for a second or so. Sans’s bony hands, almost of their own accord, found the already opened box containing the jelly-like soul, and he began rubbing his thumbs over the front of it cautiously. Mettaton reacted amazingly, his voice piping back up again, cutting out every few seconds, panting and whining occasionally as Sans mercilessly teased him, and the skeleton knew for a fact that his (deceptively sharp) nails would leave marks in the table.
Suddenly, in a moment of resolve, Mettaton’s hand reached up to his chest and flicked the dial down to the first setting again (not off, Sans noted smugly in some part of his mind that wasn’t surprised). He lunged forward, hands grabbing Sans by the shoulders, pulling him in so he was properly straddling him, now easily within reach. Mettaton’s hands snaked under Sans’s jacket and gripped his ribs decisively, and now his own breath was hitching.
“H-hey, wh… mmm,” Sans hummed, voice failing him for a moment as Mettaton rubbed at the insides of his ribs, nails latching on and making his breathing come fast suddenly, puffs of air fighting to escape. “W-wait just a sec—ahh—a second, Metta, you… nng... I can’t j-just… mmhmmfucking listen to me.”
“Now, I can’t have all the fun, can I?” Mettaton teased, and the plan was derailed, and Sans was rocking forward suddenly, and his breathing was heavy, and so was Mettaton’s, woah. He saw this wonderful satisfaction on Mettaton’s face as the television star made him cry out, his own movements faltering, and he realizes that it’s the exact same expression Sans himself wears whenever he gets Mettaton to crack. Oh god he’s the one cracking now and he can’t stop it and he doesn’t want to. His head lolls to the side slightly and he practically growls as Mettaton leans up further, eyes bragging as Sans’s movements stutter, the heart threatening to slip through his fingers. He forces himself to focus on the task at hand and he squeezes again, sharper, making Mettaton cry out once, eyes fluttering shut (how dare he have such pretty eyelashes he is a robot why does he even need those), and Sans moves to flick the dial up a setting again.
“Ohhhh my…” The sound cut in and out, and Mettaton’s head lolled backwards. His grip tightened where he had taken the shorter by the ribs, and a strangled groan escaped Sans, who tried to get his breath back under control desperately. Mettaton’s plating seemed to be hot under his bony hand. He listened for a moment and realized that his fans had shut off. Or broken. Oh well.
He found himself curious as to what the fourth and fifth setting did, despite the effort Mettaton was clearly making to distract him (one hand moving to drag his nails up Sans’s spine and oh, okay, ahhhhh man that was really nice oh man, focus… focus). He turned it up past the third setting (Mettaton was shivering and making these keening sounds and that should not have been as attractive as it was, dear god) and up to the fourth. This one made Mettaton’s breath catch, clamping a hand over his mouth as a moan carried him back down onto his elbows, head tilting back, trying to muffle the sounds he was making, but Sans was having none of that. He dropped the heart back into the container (it left a sticky, dribbling, neon pink-looking substance all over his fingers, which oddly enough he didn’t mind), his hand moving to tug Mettaton’s away from his face.
“What’s wrong there buddy, never cared about being loud before,” Sans said tauntingly, and Mettaton’s eyes flitted open, glaring daggers from beneath those (gorgeous, god damn it) eyelashes as he swallowed back a moan, breathing having gone ragged.
“F-nng… fucking bite me, Sans,” he growled, and his glare seemed to be intimidating enough, but his voice sounded shaky, flickering in and out, and his wrist was hot in Sans’s hand.
“Not with that attitude,” Sans replied calmly, and Mettaton could barely stammer a reply before he clicked up the dial one more time, and he was falling back, a shaking, groaning mess, coming apart right underneath him in a way Sans was pretty sure nobody had ever seen before, and nobody may ever see again.
(Okay, and maybe that was incredibly hot but there was no way in hell Sans would ever admit that out loud, at least not to Mettaton’s face. He would never see the end of it.)
Mettaton’s back arched and Sans watched as he tried his best to sit up, pushing himself upward on shaking arms, flicking the dial down to three again. Mettaton grabbed Sans by the collar of his jacket, pulling him into a fiery kiss (literally, his lips were hot enough that Sans made a soft sound of surprise on contact). His hand returned under the skeleton’s shirt, pressing at the inside of the ribs, then at the spine, then the lower spine, and Sans let out a soft cry against Mettaton’s lips as he felt a (hot hot hot) metal hand gripping his pelvis oh god hey there, wow, oh boy.
He was shaking now, his moans sounding strained as he tried to silence them, and Mettaton smirked, his own soft gasps still escaping occasionally. “What’s wrong, you can dish it out, but you can’t take it, hmm?”
“F… fucking…” Sans yelped as Mettaton pressed his thumb just so, and his hands found the heart (still gushing that neon-y liquid), pressing his fingers into it, not quite breaking through, but getting a bit close. Now he was pretty sure Mettaton was almost finished, and he wasn’t sure he would last much longer either, but he pushed forward, pushing, squeezing, trying to ignore just how good Mettaton’s fingers were against him and just how sexy, god, really really sexy Mettaton looked right now, a panting shivering moaning grinning bastard (his voice glitched in a way that was almost even hotter, he was literally breaking Mettaton with this, holy hell), because his pride was on the line and he’d be damned if he finished first.
He felt, more than heard, the low hum of electricity that ran through the metal underneath him, but he absolutely heard the cry (“Oh yes” and fuck now he could never hear that again without blushing like a maniac) as Mettaton arched, his grip tightening, liquid gushing, dripping, practically sizzling as it hit the hot metal of Mettaton’s legs (it was almost burning but Sans didn’t mind). He rode it out fairly quickly, his hands turning to switch off the dial now, breathing still heavy even as Sans dropped the heart back in its container, putting the lid on cheerfully.
“Well, that was sure—ah, y—“ Mettaton leaned forward, teeth finding Sans’s clavicle, hands resuming again. “Hey, y… ahhh.” A hand gripping at the base of his spine, the other at his hipbone, the front of his pelvis—breath catching in his throat, Mettaton’s smirk—
He cried out, voice fracturing, arching, head falling back, a shiver running through his body before he fell forward, hands on Mettaton’s hips, panting, gasping for breath. He swallowed hard, his sleeve wiping at his sweat-covered forehead, and he let out a whimper as Mettaton patted him on the ribs, the sensation just over the edge of too much. He felt his shirt being pulled back into place, his jacket adjusted. He finally forced himself to look up at Mettaton, who had an eyebrow raised.
“What?” he asked, bristling with embarrassment under his stare.
“Nothing. Just surprised.” Sans stared for a long moment. “Just didn’t think you’d be so… vocal is all.” Mettaton sounded almost like he was making fun, which made Sans’s face flush blue (still a bit bright from the events happening not long before).
“I’d say you were the louder one here, or at least the more reactive,” Sans said, and Mettaton glanced away. “Might wanna check your internal fans, there, Metta.”
Mettaton looked down at his chest, surprise crossing his face as he realized that they were off. “Oh dear. That… probably needs fixing,” he said after a moment’s pause.
“Well, I was supposed to check internals next, so… um…” Sans felt the awkwardness coming on.
“…Sans, was the dial even in the instructions on things you had to check?” Mettaton finally asked, eyes narrowing.
“…No.”
“Sans.”
“I’m not apologizing.”
Mettaton huffed. “You’re a sneaky, conniving skeleton and should be ashamed of yourself.”
“What, for banging the toaster?”
“Sans!”
“I’m not apologizing! And clearly neither are you, since you banged the skeleton!”
“I—is banging even the right word?”
“Probably not, but, we’ll think of something better for it later. ‘Boned’ sounds situationally appropriate, huh? Things got steamy. Things kinda sparked.”
Mettaton laid on his back, rolling his eyes. “I’m shutting off now to avoid your terrible jokes, do your stupid internals check, you… you…”
“Bonehead?” Sans suggested with a grin.
“Yes. Exactly,” Mettaton said. “Then we’re having a long discussion about what on earth we’re going to tell people.”
“Sounds good to me,” Sans shrugged, and Mettaton closed his eyes, lights dimming. Sans couldn’t help but chuckle as he picked up the list from the floor, deciding that he would have to thank Alphys later for this one.