AU Sans X Reader Long OneShots

UnderSwap Sans x Shy Reader Especially With You

Okay you are a human and well swap Sans is probably gonna be a little bit flirty. You took Pacifist, and stay at the skelebro's house and I guess you've been in the underground for a about 7ish months. You are already dating Swap Sans, I guess you've been dating for a three or four months. Suggested by @midnight_the_wolf357

"Hey Y/n!" I heard Sans yell as he jumped up in front of me. I fell back into the snow. "Ah! Sans why?" I felt a blush rise to my cheeks, as He laughed as he laid back in the snow, alongside of me. I shuffled to get up, only to have my wrist grabbed. "Don't go yet." Sans whined as I tried standing. "S-Sans." I stuttered, as he finally let go. "Come on y/n! Lighten up!" I shook my head, "Don't make a scene." I patted myself off. "Sometimes I feel like I'm the only one with any sanity down here." I mumbled, "Y/n! Don't feel bad! You boyfriend is here to cheer you up!" Sans squealed as he jumped up out of the snow. He ran over to me, as I started my walk back to the house. He picked me up from behind, flipping me, so that he cradled me in his arms. I blushed wildly, "S-Sans?" I stopped with a light smile, "I-I love you." He grinned wide as a light blush dusted his cheekbones. He giggled, as he finished my walk to the house. He pushed the door open with his foot, "Brother! I'm home! I also have brought Y/n with me!" I looped my hands around his neck, as he set me onto the ground again, I felt Sans reach his arms around my hips, pulling me closer. Sans leaned forward meeting my lips with his teeth. I pulled closer, "I love you too y/n." Was muffled by Sans into our kiss. I blushed, as Sans pulled away. He grinned, "I'll go make us some tacos!" He yelled, letting his vibrant personality fill the room. I smiled down shyly, "O-Ok." Sans jumped into the kitchen, and I started heading for the couch. "Heya kid!" I turned around stumbling backwards, "P-Papyrus? W-When did you get there?" I stumbled with my words, as much as I was falling backwards. He shrugged, "I don't know, I just pop outta no where." I let out a slight giggle as I slouched onto the couch. "Okay then." I began, "Tacos are done!" Sans yelled from the kitchen. I stood to go to the kitchen and Papyrus stood with me, but we took opposite directions. "Where do you think you're going?" I glared at Papyrus out of the corner of my eye. "Muffet's, You can tag along if ya'd like." I shook my head, "No thank you, I'd rather stay and help Sans." Papyrus held a sarcastic grin, "That's your choice kid, and I'll admit, it's a pretty good choice at that. So. . . I guess I'll see ya later then." I gave a slight chuckled, and gave me a thumbs up and a wink. "Yeah I guess so. Goodbye." I waved to Papyrus as he trudged out the door, and into the snow. I shuffled into the kitchen, to see Sans rushing around setting up the table. I already knew Sans wouldn't want help, because he thought he could do everything by himself. So I took a seat at the table, and waited for him. I heard him giggle behind me, "Sans?" I went to turn, but before I could, Sans wrapped his arms around my neck, placing his head on top of mine. I felt my face heating up again. "S-Sans are we e-eating now?" He muffled a, "mmm hmm." I smiled again, "I-I'll give you another hug after dinner, I promise." Sans gasped running over to his plate to begin eating. I have to admit, his tacos aren't the best, but they have gotten so much better since I've been helping him. I only ate one taco, but Sans ate like six or seven.

As Sans was finishing his last taco I stood to go to the living room, "Where are you going?" Sans said with a mouthful of taco. I shrugged, "To the living room, I guess." Sans began eating again, as I walked to into the living room. I flopped down onto the couch, and went to find the remote for the tv. I have always wondered how Sans could eat so much so fast.I chuckled to myself, He doesn't even have a stomach. "Y/n!" I heard Sans call from the kitchen, "I'm coming for my hug!" I heard Sans foot steps, as he half ran, half walked into the room. He sat beside me and I huffed as I wrapped him in a snug hug. "Is Papyrus home?" Sans whispered in my ear, "N-No, why?" He giggled as I asked, "Y/n do you mind if I try something." I paused, "Depends on what it is." 
(Awkwardness and I know blueberry is innocent. Wait and you'll get an explanation)
"Nothing bad, I swear!" He looked flustered, with a blue blush roaring across his face. What is he planning now. He slowly pushed away, before moving to kiss my neck, "S-Sans!" I squeaked as he moved down my neck, "Wh-what are y-you doing?" He sat up, confused, "Undyne told me this is what you do if you really really love someone." He pushed me on to the back of the couch, and dark blush formed on my cheeks, "You really love me, right y/n." I felt the blush on my cheeks darken, "Y-Yes S-Sans, but not like t-this," I stammered out. As he continued kiss at my neck, he climbed over top of me, sitting on the tops of my thighs, he leaned in close, kissing me. I felt something brush against my teeth, Skeletons have tongues? I would have leaned back, if I wasn't already pinned against the couch. Sans leaned back, with a disappointed face, "Y/n, Undyne said if you really love someone, you do this, but you won't kiss me back. Why won't you kiss back Y/n?" Sans seemed to have the concept wrong, "Sans I-I'm sorry but-mhrp!" I muffled as Sans suddenly rushed his face to mine. His tongue entered my mouth. His tongue eagerly explored my mouth, brushing at my tongue." Sans pulled back, A gleam of achievement in his eyes. I placed a hang over my lips, startled by the sudden and different kiss. He then kissed behind my jaw, and when I thought he would leave, he took his tongue gently down my jawline, and down my throat. I covered my mouth, preventing a small moan from escaping. "S-Sans p-please, d-don't do that." I gasped, Sans held a sad, innocent look. "D-Did I mess up again." Sans eyes had turned from there usual stars, to regular eyes. "N-No Sans. I-It's just that-" Sans leaned in closer to me, "Undyne said some people don't like this kind of stuff, but they can warm up to it." He kissed me, gently this time. I gently stoked my hair, and his other hand, had his fingers draw little shapes over my skin. Sans pulled back, "Y/n I lov-"
(Awkwardness over)
*Ring Ring* I jumped as the phone rang, Swap jerked back further, "I'll get the phone!" Sans said as he jumped off of me, running to get the phone. I sat up, Did that just happen? I watched Sans as he answered the phone. "Hello this is Sans speaking." He called into the phone, "Oh. . . I'll be right down. Just give me a minute." He hung the phone up. "Is something wrong Sans?" I questioned, as he turned with a tone of sadness in his eyes. "Papyrus is drunk again at Muffets." I stood up, "Sans, come here please." I sounded more sure of myself than I usually am. Sans walked to me, as I held my arms out for him. He slouched onto my shoulder and began balling his eyes out. I was able to drag him to the couch, feeling tears of my own form in my eyes from the words he was sputtering out, "I don't know why he does that to himself! And why he babbles on about timelines! I just- I just- I just don't understand!" I stroked the back of his head gently as he spilled his worries out to me. "Listen Sansy I'm gonna go get Papy ok." I told him, He looked up at me, as I wiped his tears off of his face. "Y/n, I'll miss you." He sniffed to me, "I'll only be gone a little bit, alright, I promise." He ran his hand behind my back, bringing me into a kiss. I didn't pull away, but I barely kissed back. Swap closed his eyes, and I closed mine. I finally pulled away, taking a deep breath. Sans face held a blue blush from the kiss and the tears. "I'll be back soon Sans, I promise you." I stood to leave the couch, having my wrist grabbed and pulled just a bit, "I'll see you soon, Y/n." Sans whispered to me. "Same to you Sans."