Undertale One-Shots

Underswap!Sans X Reader

You skipped happily through Snowdin, your thoughts filled with a certain small skeleton. You couldn't wait to see Sans! You had arranged to go to the skelebros house today, and you were excited. You strode up to the skelebros house and knocked on the door, and a tall skeleton with an orange hoodie opened it. You smiled at him.

"Hey Pappy!" You greeted, giving him a brief hug. Papyrus chuckled and hugged you back.
"Sup Y/N." Paps said, "It's good to see ya. Come in.". He moved out of the way for you to go inside, lighting up a cigarette as you did so. You jokingly glared at him and wandered into the kitchen, where Sans would usually be. You saw him with his back turned to you, holding a bottle of hot sauce. You tip-toed up behind him, trying to be quiet, before pouncing on his back. Sans yelped in surprise and accidentally squeezed on the condiment bottle, which resulted in both of you being covered in the sauce. Sans groaned and turned to look at you.

"Y/N! Did you have to do that?!" Sans scolded, with hot sauce dripping off of him. You both looked at each other before bursting into laughter.
"You really are silly, Y/N." Sans chuckled. You smiled goofily at him.
"Yeah, I'm not gonna deny that. Ummm, we may need a change of clothes..." You muttered. Sans nodded and told you to stay put, and he raced up to his bedroom. You heard Papyrus snorting and laughing.
"OH MY GOD SANS, YOU LOOK...WOW. GETTING SAUCY WITH Y/N, HUH?" Papyrus wheezed, crying due to laughing so hard. You sniggered to yourself at his pun, as you heard Sans scolding Pap. A few seconds passed before Sans returned with a change of clothes for you, with him being already changed in a blue hoodie, black shorts and some white trainers.

"Here, I grabbed some of Paps' clothes for you. Mine are too small for you." Sans said. You thanked him and went into the skelebros bathroom to get changed. You were gratefully surprised that none of the sauce was in your hair. Once you changed, you headed back into the kitchen, where you saw Sans preparing ingredients.

"Making tacos?" You asked. Sans nodded happily.
"Yup! Wanna help me?" He asked.
"Sure!" You replied, and started preparing some salad.
"I can't believe you ruined my battle body..." Sans sighed, a small smile on his face.
"I'm sorry, I didn't expect you to react that way..." You chuckled.
"It's fine Y/N. The sauce can be washed out." Sans replied. You both finished making the tacos and headed into the living room, where Pap was sitting on the couch watching Napstabot on television.

"Ooooo! Napstabot is awesome!" You exclaimed, whilst the bros chuckled.
"Yup. I see you both made some tacos." Paps observed. "Any hot sauce left for them?" The taller skeleton snorted, whilst you chuckled and Sans sheepishly smiled.
"A little, Pappy." Sans said, and went to go get the hot sauce. He returned shortly, and you all ate the tacos with whatever hot sauce was left. Afterwards, Papyrus stood up and claimed that he was going to Muffet's.
He left, and you and Sans sat on the couch comfortably snuggled up to each other. You were glad that Sans was a naturally cuddly guy, as it meant you could cuddle him without him figuring out your feelings for him. You both continued watching Napstabot perform, humming along to his songs. You had noticed that over time, Sans was holding you closer than before. He also was blushing a little bit, which confused you.

"Sans?", you asked, "What's wrong? Why are you blushing?". The small skeletons blush grew brighter.
"Um, well... I really like cuddling you... You're very cute, and sweet and... Lovable..." Sans mumbled, his blush now a vibrant blue. Your face was beginning to turn a light shade of red.
"W-What do you mean...by lovable?" You questioned. Sans squeezed you lightly, looking into your eyes.
"W-Well, I r-really like you, Y/N! M-More than a friend! I have done for a while now and I didn't w-want to hide my feelings for you any longer!" Sans exclaimed. Your eyes widened, your heart skipping a beat at his words. Before you could say anything, Sans pressed his teeth against your lips. You closed your eyes. The kiss felt...weird...but in a nice way. The kiss lasted for several minutes before you both broke away, panting slightly.

"Wow..." You panted. Sans' blush was as dark as a blueberry, and yours was as red as a strawberry.
"Heh... I couldn't hold back..." Sans smiled. You smiled back and hugged him tightly.
"I'm glad you didn't hold back. I like you too Sans..." You whispered.
"Y-You do?! Wow! The magnificent Sans succeeded!" He cheered, fist pumping.
"Succeeded in what?" You asked, confused. Sans smiled and held your hand.
"I succeeded in capturing your heart!" He chuckled, and you blushed.
"Did I capture yours too?" You asked. He nodded and kissed you lightly. You smiled into the kiss.

You knew that this was the start of a beautiful relationship.