You could not believe this would happen to you.
You had planned on sleeping over at the skeleton brothers’ house for the night (at Papyrus’ insistence, of course) and sped over for one of your recurring movie nights. What were movie nights without comfy pajamas and friends? You already had the ‘friends’ part covered, Papyrus setting up the movie and Sans still upstairs, so you just needed to get the pajamas part down. You scampered upstairs and into their bathroom, but oops, you’d accidentally left the door slightly ajar.
This wouldn’t have been much of a problem, had Sans not walked by at that very moment and seen you through the three-inch crack of the door. With your shirt dragged up over your exposed breasts and panties barely clinging onto your hips, you accidentally created the most erotic pose you’d ever been in. Your body twisted in a way that pushed your ass out toward the door frame, catching his already heated gaze. That was, until you began gathering your things. He left, and hey, you hadn’t even heard him pass through. You finished your business (overly large shirts were the best) without noticing anything was awry and only huffed at the sight of the barely-open door.
However, on your way back downstairs, clothes in the crook of your arm, you heard a peculiar noise.
From Sans’ room.
The door of which was about three inches away from being completely shut.
The sound only got louder as you tried not to drag your feet, getting closer. Oh, yup, that was panting. And also, very, very furious rustling noises, accompanied by something that sounded like the clicks of plates against each other. The sounds were… quite…
You peeked in nonetheless, not about to pass up your curious tendencies. You couldn’t help it, you swear! You just needed to know what those compromising noises were, and why they would be coming from his room. Your eyes adjusted to the shift in light as you peeked in and –
Your jaw dropped. Literally what were you looking at right now? With the slightest blue glow added to the dark room, you observed Sans, the rung of his sweatshirt crammed between his teeth and his hand furiously working at an erect cock at the base of his shorts. There was no ceremony to it – Sans the skeleton, the comedian, one of your best friends, was fucking masturbating.
And knowing that, seeing that, you immediately felt a shock go straight to your panties.
The freakin’ scandal – if he knew you saw this – !
… But wait. He was doing it all wrong. At the moment, Sans pumped at his erection as if his arm were about to give out. His phalanges barely skimmed the tip of his dick before going straight back to the middle, up and down, no technique in it. Desperate. Frantic. The sight made your breath quicken, but something bothered you about it.
He was close to releasing, you could tell, but you couldn’t allow it. He couldn’t finish like this, not when his technique was this bad.
You pushed the door open just enough, slipped through, abandoned your changed clothes, and shut the door. The click of the bolt shutting alerted him much so that his entire frame, previously shaking from exertion and desire, stuttered to a halt. A muffled yelp came from behind the grip his teeth had on his sweatshirt and his cock throbbed in his hand.
He made no move to cover his cock, still in an iron grip, but his eyes, wide, kept your gaze away. You stepped forward once. He didn’t move. You stepped again, slowly, swaying a hip to steady yourself. He stayed stock still.
From his seat on the edge of his pelvis, the mattress barely supported him, which left you just the right amount of room to take a seat behind him. Your chest brushed his back as you straddled his backbone. Your legs wrapped around his hips and under his thigh bones.
You leaned up to his skull and said, lowly, “You’re doing it wrong,” and you savored the shutter that wracked through him. His head tilted toward you and your eyes met once more.
Instead of a deer in headlights, this time they dared you to do something, anything. His white pupils, blown wide, stared half lidded at you in a way that made your heart pulse in your ears. A blaze of heat built in your belly as you slowly grabbed his hand in yours and guided it to the tip of his cock. With his head still facing you, you felt a short breath escape onto your neck.
“Stroking like a madman won’t be satisfying. Start from the tip,” you said softly, taking his thumb and forefinger and wrapping around the tip as you stated. “Work your way down…”
You could feel the heat of Sans’ magic even through his hand – you guided him down to the base and constricted your fingers, holding him there as he groaned low, the heat building. You had to resist grinding into him after feeling the guttural sound reverberate through you.
“Don’t pump. Twist.” You twisted your wrist and both his hand and yours came back up to the head of his cock – you both sucked in a breath as his pelvis ground into you like you’d wanted. His skull dipped into the crook of your neck where hot sweat mixed between you. He breathed your name and, shit, you wanted to climb onto him so bad… but you returned your hands to the base of his cock, held his hand firmly to work himself up again, and twisted.
Down. Gasp. Twist. Up. Down. “ngh…”
Your other hand grasped his other, and you brought that thumb to the slit at the tip of his cock; “You’ll cum quicker if you tease it.” His thumb pressed at the accumulated pre-cum at the tip and he nearly doubled over in your arms, a warbled moan erupting from somewhere in his non-existent throat. You moaned with him and finally gave into that desire to create some friction between you and his spine. Each roll into him drove you crazy and you felt your own wetness soak into your shorts. In a clouded sense of pure lust, you almost lost concentration from your original goal.
You wanted to make Sans cum. You wanted to make him cum hard.
Twist. Up. His thumb rubbed the tip again and it only egged you on more with the way his hips stuttered forward. “i – i – !” he attempted, voice deep, and you smothered the utter desire to ride him to completion.
“Do it,” you breathed. And he violently shook, and you quickly shoved your hand into your panties to rub yourself as he shot strands of translucent cyan cum onto his sweatshirt. His head lolled onto your shoulder, his chest heaving and his fingers constricting in the grip of one of your hands. Your other swiped furiously, desperately. You needed to finish with him, needed to cum too, but suddenly you found your wrist restrained from moving. Your heat pulsed.
His voice shook from his release; “you’re doing it wrong,” Sans said breathlessly into your neck. You shuddered behind him and his hand guided yours back into your shorts, against the wetness of your lips. You nearly came from the realization of the tables being turned.
His phalanges encased yours and cautiously delved between your folds – you whimpered, not bound to last after all of that. His thumb guided yours to your clit, rubbing just enough that, paired with his mouth suddenly enclosing that one sensitive spot on your neck, you howled with the sensation of your release. A flow of heat washed over you as you physically shook. One last whine escaped you – you slumped against his back as he had done to you before and you both shared a moment of stillness, hands entwined, wet, and the room still glowing an ethereal cyan.
“I think… you’ll have to give me a real lesson soon,” you mumbled against his shoulder. You gave it a solid kiss, to which he rumbled a tired laugh.
“next time, we’ll be learning all the best places to eat out,” he replied, and you snorted, if only to cover up your newfound arousal. You made to place another kiss on his neck, when –
“BROTHER? HUMAN? WHERE ARE YOU? PAJAMAS DO NOT TAKE TWENTY MINUTES TO PUT ON!”
You both froze and shot up faster than bullets. “Movie night,” you said at the same time, frantically straightening yourselves out. Sans didn’t seem to know what to do with the multitudes of substances all over him and you shrieked when he shrugged, hands in his pockets and himself on the move toward the door. He intended on going into the living room with glowing blue jizz on his sweater? Yet he only snickered at your mortified look.
You glared. “Don’t you dare leave this room with your stuff smeared all over you.”
“ok, i’ll leave this room with your stuff smeared all over me.” And he took his hand. And he wiped your cum across his chest.
“Don’t. You. Dare. You take that nasty sweatshirt off right now!”
“Sans the skeleton, you get your bony ass back here!”