Sans x Reader insert (Undertale Smut / Lemon)

Human!Sans x Male!Reader

"God, do you seriously suck at every videogame we play?" You chuckled, Sans grumpily throwing down his controller. "I'm not used to this human shit, dickwad." You rolled your eyes, pausing the game. "Yeah, yeah. I know." You got up and called your local pizza place, since Sans was the loser, he had to pay.

You placed an order for a cheese pizza, Sans asking for ....ketchup? on it. Thankfully, they didn't offer it as a traditional topping, but would include some ketchup packets.

"Hey."
"What?"
"If I beat you in another game, how about you pay me back?"
"God you're so cheap."
"Shut up, deal or no deal?"
"Deal. But if I win, I get your pink slippers."
Sans smirked to himself. Almost as if he knew you'd lose. "Sure, buddy. Deal."

It didn't take long for one thing to come to another. Next thing you knew, Sans was slipping off your boxers and you were pulling his shorts down.

He forced you down on your knees. You were gonna have some fucked up carpet burn after this. "I hope you know how to give a good blowjob." He smirked, his thick, veiny cock falling down onto his thighs. "Shut up." You grumbled as you grabbed his member, beginning a simple up and down motion with your hands. Sans moaned contently, laying his head back onto the couch. You ran your tongue around from the base to the tip, paying extra attention to the head. "Someone must do this often." He teased, running his hands through your (h/c) hair. You kept your focus on his cock, licking and gently sucking as you bobbed your head up and down on his shaft. "Fuck.." You smiled, looking up at him as he looked down at you. "Alright, get up here." You gave his manhood one more kiss as you got up. "You sure we can't do this in the bedroom?" You sighed, getting on all fours.
"More humiliating for you here."
To an extent, he was right. You'd definitely have to clean up any mess quicker since your parents would be home in a few hours. He lightly stroked your backside, giving you a few small tingles. "Put it in already." You whined, earning a rough slap on the ass. Huffing, you retried your approach, "Put it in, pleaseee."
Sans chuckled as he slid his fingers in your mouth, you sucking on them obediently while mentally preparing yourself for the trauma your asshole was about to endure.

He slowly slid in one finger, then the other. You let out a deep sigh, letting soft moans escape your lips as he began to thrust his slicked fingers in and out. "Ready?"
"Ready."
Gyrating his cock around your entrance, it wasn't hard to tell he was toying with you. You whined each time, the pressure feeling as if he was about to do it- but never did.
He teased you a bit longer, before slamming his length into you. It caught you a bit off guard, you let out a loud gasp, followed by a low moan. He pumped into you, his hands on your waist to move you along at his tempo.

You moaned loudly each thrust, your knees already weak only a few minutes after he started. Just as you were getting used to the feeling, he slammed into you harder. "Fuck you." You managed to say between a mix of moans and whimpers. The sound of your two bodies slapping together filled the living room. You don't even remember turning the TV off. As Sans began to slow down, he reached around you, grabbing your cock in one hand while still gripping your waist in the other. He slowly began to pump your cock, his motions quick and hurried enough to be your breaking point. You held it in, though. Cumming first meant you'd lose.

...Sadly, you couldn't hold it long. Sans quickened his pace, jerking you off faster as he continued his slow thrusts. You let out an extended moan as you came all over his hand. And the couch. Great. Sans came right after you, filling your asshole with so much of his cum that it began to drip onto the couch. Double great. Both panting heavily, you plopped down on the couch, dirty or not- your legs weren't holding you up much longer anyway. Sans coaxed his now soft member back into his boxers, then slipped back into his shorts.

"I'll be waiting for my prize money."
"....Fuck off."