Dinnertime was “family hour”, Alphys asserted on more than one occasion; the only time she felt strongly about her and Mettaton taking a moment between their busy schedules to just sit down, enjoy a meal together and share the goings-on of their respective days.
Seeing that Mettaton was incapable of consuming food and that Alphys had a bad habit of not knowing when to stop talking once she began, however, “family hour” was more “Alphys’ talk therapy hour”.
Mettaton didn’t mind, particularly. He was very good at giving the impression of being absolutely fascinated with the ins and outs of Alphys’ scientific pursuits; leaning over the table and letting his eyes dance around her face as she babbled, pretending to hang on to her every word.
As Alphys chattered away as usual on that particular Friday evening, Mettaton noticed that her forked tongue flicked out just beyond the confines of her scaly lips every time she pronounced anything with a “s” sound; today, for some reason, it was fascinating to him. He sipped pensively at his champagne glass of oil, large purple eyes trained on Alphys’ mouth.
“--and I don’t know, I don’t want anyone thinking this is weird,” There goes that tongue again, “thith ith weird”, hah, “because it is keeping a m-monster tied up in the basement, not to sound like a s-serial killer or anything--”
Mettaton choked on his oil, not certain he had heard Alphys correctly. “Come again? ”
Alphys blinked. “I don’t wanna sound like a s-serial killer.”
“Oh! Papyrus is tied up in the True Lab.”
Mettaton inhaled slowly, air whistling audibly through his metal nasal canals, before setting his glass camly on the table and smiling at Alphys. “Right. Might I ask… why?”
Alphys’ brow furrowed. “Haven’t you been listening? I’m running a t-test on the effects of a monster’s period of heat on their c-cardiovascular function, and P-Papyrus volunteered to be a guinea pig, so to speak. You see, I’ve theorized that--”
Mettaton held up a hand. “So, what you’re telling me is: you have Papyrus, in heat, tied up underneath us right now.”
“A-ah…yeah? N-not for anything, w-well… y-yaknow.” Alphys trailed off, her eyes begging Mettaton to take the hint.
“I don’t think I do,” Mettaton said mischievously, “You’ll need to elaborate.”
“Oh, Mettat-- ugh. I’m saying that everything is purely s-s-scientific. Absolutely p-professional. I’m only s-studying the effects on the soul, what the d-d-d-difference is between a s-state of rest and d-during heat-- ”
Alphys continued on, tripping nervously all over her own words, but Mettaton was too deep in thought to be amused.
He had met Papyrus a few times before; Undyne usually dropped by the lab with him in tow, and while Undyne and Alphys visited it was Mettaton’s job to keep Papyrus entertained. After a while, Mettaton began inviting the skeleton over without the pretense of Undyne’s visiting; he very much enjoyed Papyrus’ company. He was genuine, excitable, always had a compliment for Mettaton at the ready and was, admittedly, rather handsome…
Mettaton had given the enthusiastic skeleton a tour of his bedroom, so to speak, on a couple of occasions before. His lovemaking was always supremely sweet; he was nervous the first time and endearingly considerate of Mettaton’s needs for the rest of them. The thought of him-- such a gentle-skeleton-- going into heat was certainly a strange one. It was a time of feverish desperation, high body temperatures, foggy memory, blurred vision, and… well. A certain insatiability.
Not exactly the first thought that came to mind when considering the proud, goofy Great Papyrus. It piqued Mettaton’s interest.
Alphys seemed to sense this; her eyes immediately narrowed in response to the prurient smile tugging at Mettaton’s lips. “The lab is off-limits, Mettaton.”
Mettaton blinked innocently. “Me? Interfere with your experiments? Never.”
Both of them knew this to be ludicrous. Mettaton had just last month set Alphys back to square one with her tests on the phosphorus material in Waterfall’s plants by using it as eyeshadow. Yes, dipping his fingers in it tainted all of her painstakingly collected samples, but it really looked fantastic on him, so, c’est la vie!
In any case, Alphys didn’t trust Mettaton one bit. Not with that look on his face.
“I’m serious, Mettaton. I know you and Papyrus are friends, but I don’t want you going down there. He isn’t the Papyrus you know… he’s not in control of his facilities.”
Mettaton realized that this information was supposed to deter him; it only served to further his interest. Still, he consciously put on a poker face, feigning nonchalance as he began to devise a plan.
“Promise me you won’t go down there?” Alphys pressed, “I don’t want to have to put a lock on the door--”
“Wouldn’t dream of it, darling. Really. I’ve learned my lesson from the whole eyeshadow fiasco. I don’t want to ruin any more your experiments.”
Alphys stared Mettaton down from across the table for a long while, watching him pick up his glass of oil again and take a sip, seeking to detect a hint of sarcasm or deceit. There was none; he seemed genuine enough, so Alphys relaxed into her chair, her mind somewhat at ease.
Mettaton happened to be a very, very good actor; unquestionably the Underground’s very best. And so, while Alphys did her nightly Sudoku and prepared herself for bedtime, Mettaton excused himself to his room to choose an appropriate outfit to serve in setting his lascivious “plan” in motion.
He selected his outerwear first; a silky, maroon kimono robe that he knew hugged his curves rather deliciously. It conveyed a “I’m being innocently sexy”, “I’m just off to bed to charge, looking devilishly handsome as usual, don’t mind me” sort of message. Laying the robe out on the bed, he shed his armor piece by piece until he stood naked before his monstrosity of a closet, considering what he wanted to put on underneath the robe.
MTT-Brand lingerie was a booming business in the Underground; each piece was designed with utmost care, using only the best lace and the softest fabric. Mettaton owned one of each; now it was simply of question of which one. A peach-colored bustier caught his eye and he pulled it down from the rack, inspecting it closer. It was certainly cute enough, but the garter hooks on the bottom wouldn’t look so nice without being attached to full stockings, which was a little less “easy-access” than Mettaton liked. It was more of a performance piece, he decided; Mettaton carefully put it back on its hanger, eyes scanning the broad selection once more.
He withdrew a black babydoll; the color was nice, but it covered up a little too much. A red bodystocking? Way too baudy; Mettaton prefered to be a tease, starting slow and working up to overt lewdness in his sexual pursuits.
He paused, half-turning back to the robe on his bed. Why not... just that?
Pulling it on his shoulders, relishing in its delightful slick softness, and tightening its ribbon tie around his waist solidified his decision; it clung enticingly to his hips and chest and was just barely long enough to cover his shapely behind. Perfect.
Peeking out from his room, he confirmed that there was no light emerging from under Alphys’ door before slipping into the hallway and padding down to the elevator which would deliver him to the True Lab. The hall was completely dark, but his eyes had night-vision capabilities so turning on the lights and risking rousing Alphys wasn’t necessary.
Mettaton didn’t know his way around the True Lab quite as well as the upstairs; it was rare that Alphys allowed him to be down there, but he found Papyrus easily enough once he departed the elevator and ventured inside. The skeleton monster, dressed in a green gingham hospital gown, was bound with metal cuffs circling his wrists and ankles to a padded chair. He was dozing with his head hanging to his sternum; for being in the middle of heat, he looked surprisingly peaceful.
Papyrus raised his head, and Mettaton immediately took note of the savageness in his eyes; they were glowing brighter than he’d ever seen, blazing like a fire in a hearth. “M-Mettaton! I wasn’t expecting--!”
His voice faltered as he drank in the full picture of Mettaton, who was now standing directly before him with hip cocked sensually to one side, the heart-shaped LED’s in his eyes pulsing softly in the dim light of the lab.
“I heard you were spending a few nights down here… and you didn’t even tell me! Tsk, tsk, and I thought we were friends...” Mettaton scoffed, the left corner of his mouth turning up sharply into a smirk, “Anyway, I figured you’d be lonely, so I thought I might pay you a visit.” He began to toy with the ribbon circling his middle with delicate fingers. Papyrus clearly couldn’t stop himself from staring at Mettaton’s hands, the hunger in his gaze prompting a low chuckle from the depths of Mettaton’s throat.
“Very kind of you, Mettaton, v-very kind… I apologize for being in such an awkward position c-currently, tied up like this, it’s h-hardly presentable but it’s for your safety, see--”
“Mmm. Don’t be sorry, darling...” Mettaton hummed, loosening the ribbon considerably and allowing the robe to slip off of one broad shoulder, “Safety first.”
Papyrus groaned at the sight of Mettaton’s bare gray skin, and then blushed considerably. “O-oh, Mettaton,” he pleaded softly, squirming in his chair, “P-please… I’m…I’m...”
“In heat?” Mettaton suggested teasingly, “Desperate for me? Dying to… hmmm... cram me full of your cock and... fuck me within an inch of my life?” Mettaton giggled at Papyrus’ shuddering gasp, relishing in his desperation, “How naughty. I never knew you had it in you, Pappy-dear, you’ve always been such a gentle-skeleton.”
Papyrus whimpered, hips bucking forward as Mettaton allowed the ribbon belt to drop to the floor, his robe falling open completely and revealing his glowing soul and fully hardened pink erection. Drifting forward until he loomed over Papyrus, he rested a hand on the skeleton’s shoulder blade and swayed his hips from side to side, staring into his eyesockets with a grin plastered across his face.
“I love to feel desired…” Mettaton murmured after a moment, allowing his other hand to wander down to his glittering cock. His silicone fingers danced across his length as Papyrus watched jealously; the skeleton’s body shook with savage anticipation as Mettaton whimpered at his own touch.
“Oh, Pappy,” he breathed, his head tipping back as his hand closed around his cock, “I’ve been so pent up… tell me how much you want me…”
“P-Please… please, please…”
Mettaton slid his fist up and then back down to the base, triggering his self-lubrication system and dampening the inside of his palm. “Please, what?”
“Please… I’ll g-go insane…nyeh...”
Mettaton pulled on his cock, gasping with pleasure, Papyrus’ pleading only serving to spur him on. “Good god,” he gasped, “That feels amazing… I bet you like watching this, don’t you? D-dirty boy.”
“Yes! I’m a dirty boy, I’m such a dirty boy, oh, please,”
Mettaton jerked harder, moaning softly, Christ, Papyrus begging like this was really doing a number on him,
“Mettaton, I need you, don’t do this to me, please, I need you, I adore you, p-please, FOR THE LOVE OF FUCK, PLEASE--”
Taken aback by the skeleton’s uncharacteristic use of a curse word, Mettaton decided perhaps he had lorded his freedom over the skeleton a bit too much. Humming with satisfaction, he removed his hand and bent at the knees, lowering himself down onto Papyrus’ lap and grinding on his pelvis through the fabric of his hospital gown. Papyrus was rock hard; he twisted his hips desperately beneath Mettaton, gasping at the welcome friction.
“AH! METTATON!” Papyrus’ right eye lit up orange like a flame, “I’M SO C-CLOSE!”
“Tell me when,” Mettaton hissed in his ear canal, rocking back and forth with earnest against him before pressing his soft lips to his skull. “Oh, darling, come for me!”
“O-OH! WHEN! W-WHEN! I’M GONNA-- OH METTA-- METT--”
Mettaton stood up at once, leaving the skeleton a quivering, unfulfilled puddle before him in the chair. Papyrus keened fervently, browbone furrowed in savage frustration, the metal cuffs rattling as he jerked like a madman against them. All semblance of the polite, fairly innocent skeleton that Mettaton knew was gone; he was purely animal, tugging at his bonds, snarling, desperate tears welling up in his eyesockets. God, what a sight. Who would have thought… the Great Papyrus…?
Mettaton crossed over to the True Lab’s control panel and found the switch for Papyrus’ metal cuffs. Before flipping it, he turned his head back, biting his lip as he took note of the feverish desire in Papyrus’ eyes as the skeleton stared him down.
Hmm… maybe just a little more teasing…
Mettaton bent over the panel and flipped up his robe, exposing his ass to Papyrus. He giggled at Papyrus sharp intake of breath; the rattling sounds grew louder and more keen as Mettaton spread himself apart for the skeleton with both hands, allowing him to admire what he couldn’t quite reach.
“Like what you see, darling?” he murmured, but Papyrus had descended into his heat deeper than the ability to articulate. He could only growl throatily in response...
Mettaton straightened up and finally tossed the switch, turning back to Papyrus as the cuffs slid away.
Papyrus got to his feet, jaw slackened and tongue lolling from between his teeth. His eyes-- one a faint orange dot, the other filling the entire socket and blazing dangerously-- were fixed on Mettaton’s form across from him; his ribs heaved and a trickle of saliva escaped his mouth, sliding down his chin.
Mettaton smiled pensively at him before allowing his red robe to drop to the floor, pooling around his ankles...
Papyrus charged like a raging bull, knocking Mettaton back against the tile wall of the lab. Mettaton squealed with enthusiasm as Papyrus spun him around ferociously, bending him over and taking him completely with one brutal push of his hips; his throbbing cock was slick with viscous orange magic and disappeared inside Mettaton with ease. Mettaton steadied himself against the wall with the palms of his hands, crying out passionately as Papyrus thrust with all of his might, his phalanges scratching at Mettaton’s back, tugging at his hair, digging into the soft silicone flesh of his ass.
“O-oh, oh yes, oh yes, oh yes, a-ah--” Nonsense spilled from Mettaton’s lips as Papyrus rutted into him. He’d never had such a rough fucking in his life and, god, was he loving it. His circuits buzzed and crackled with electricity, soul pounding against the glass confines of his stomach, he was practically being torn apart by Papyrus’ cock and he couldn’t get enough of it, molten hot pressure was building in his groin, all of his senses were practically on fire, set ablaze by Papyrus’ animalistic ferver--
Papyrus bent over Mettaton’s back, encircling his strong arms around the robot’s chest as he sped up even more. He was snarling into his ear and Mettaton couldn’t take it anymore-- with a harsh cry of ecstasy he splattered the wall and floor in front of him with hot pink cum, whimpering with the exquisite soreness of overstimulation as Papyrus continued his ruthless pounding--
Papyrus howled, finally, emptying himself inside Mettaton. His hips jerked, juddering as he lost his rhythm and sliding out of Mettaton suddenly, “GOD, I CAN’T STOP!”, he came a second time up the length of Mettaton’s back, “I C-CAN’T STOP--”, he gripped his cock and jerked it, Mettaton fell to his knees and turned around just in time to take a face full of Papyrus’ third consecutive orgasm…
Papyrus stumbled backwards on shaky legs, his eyelights dimming, before collapsing to the floor with exhaustion. The two lay on the floor for a moment, their heavy breathing the only sound in the silent laboratory, before Papyrus crept forward on hands and knees and rested his head in Mettaton’s lap.
“W-wowie,” he breathed into the robot’s thigh, and Mettaton recognized the shaky, high-pitched nervous voice of the Papyrus he knew; the heat was over.
“Good gracious, darling,” Mettaton chuckled, petting Papyrus’ skull, “What fun!” Sorry, Alphys...
But Papyrus was already drifting off to sleep, eyes closed, the silly, satisfied grin on his face illuminated by the soft effervescence of Mettaton’s soul.