Under the mean face(Underfell Sans x reader)[COMPLETED]

The barrier

The pling of the elevator indicated us that we were arrived. We all entered in a blank white corridor. It wasn't really comforting so my grip on Sans tighten a bit. He looked at me then squeezed my hand back, smiling in a comforting way. His gaze trailed back to in front of us. As we walked, a couple of monsters passed us, not without bowing in front of the king of course.
~time skip~
After thirdy minutes of walking, we finally arrived in what seemed to be a throne room. Golden flowers all around the floor, but some of them were rotten or had missing petals. He led us passed the throne and we entered a dark place. He formed a fireball in his paw and throw it to the wall, lighting a torch, he did it a few times until we could see the whole room. It was a circular cave with a table, a couch beside it and some chairs around it. There was a long oval hole, not so far from the entrance, where water was flooding then falling in an other hole to drain it somewhere else. There was some shelves with numerous boxes of tea and a big tea-pot. He asked us to take a sit, I was about to sit on a chair, but Sans placed himself underneath me so I would land on his lap. I blushed as I saw that and my face became even reder when he wrapped his arms around my waist and laid his skull on my shoulder. He pecked my cheek and then looked back at the king who used his fire magic to heat up the water. The goat man dropped a bag of tea in the boiling water then served us small cup of the warm liquid. He sat in front of us and calmly sipped his tea, swallowing the liquid before talking.

Asgore- I'm sure that Sans already told you what we would need to break the barrier, so if you do not want to proceed this way, I'll give you a week to find another way. I'm sure Sans will be able to help you with the scientific things. Don't you, Sans?

I felt Sans tensed up a bit. I thought about it for a bit. Ok, maby I have an idea, but for that, I need to know....

You- Who.... Who here has the highest LV.

Sans and the king choked on their beverage and coughed a bit before staring at me with wide eyes.

You- I know it's a bit weird, but the LV determine your strength, so if we take the most powerful monster and let him absorb the souls, he should be able to break the barrier. Right?

Asgore- ....... Hmmm..... That seems logical. But we're not sure that it'll work. Look, just search a way and if in one week you don't have anything, then we'll do that. For now, you may dispose. Goodbye.

I waved goodbye and Sans used his shortcut to bring us back in front of Grillby's. He huffed a bit and cough, I looked at him with worry in my eyes.

Sans- It's nothing (y/n). Don't worry about me.

You- Nope, you're not getting away like that. I'll carry you.

Sans- Wha-

I didn't even let him the time to protest that I picked him up bridal style and walked toward his house. He blushed and struggled a bit, but when he saw me face, he gave up and only cuddled closer to me. I received some weird stares from passing monsters, but I ignored them and continued to walk. Once arrived on the porch of the house, I opened the door and closed it with my foot. I climbed up the stairs and went into our room. I laid down, still carrying Sans and he stayed on me. He shifted to a comfortable position and slowly closed his eyes, hugging me softly and falling asleep. I smiled and heard the front door swung open, probably Papyrus. I heard quick steps and the door to Sans and I's room opened a bit. Papyrus peeked through the door and I signalled him to come. I wore a huge smile when he saw me and rushed silently near me. I pushed myself so he could come. He sat down on the edge of the bed and hold me hand, some tears fell down of his eye sockets. I smiled comfortingly and brushed the tears away with my hand. I whispered that when Sans'll woke up, I'll go see him. He left the room after a bit and closed the door softly. I looked back at Sans and gently pet his skull, slowly drifting off to sleep.
~time skip~(three days later)
I passed two days with Papyrus, turns out that he really missed me. He had been all kind and caring after I told them the whole "lab" story. Me and Sans actually thought a lot about different ways to open the barrier. So, here's our options.

#1- Take the monster with the highest level and let him break the barrier. But we need to trust him or else, he could use badly this power.

#2- Make an artificial soul. Sans told me that the old royal scientist already tried it, but it didn't worked out. (He seemed reluctant about the subject)

#3- Sans wasn't agreeing, but it's still an option. Take my soul and use it to break the barrier with the other ones.

Only three options for such an important thing. If the barrier did broke, me and Sans talked about the fact that I could teach humans laws to the monster so there's no war. It was a pretty good idea, in my opinion. Since today was only the third day and it was late, we didn't dug deeper in the case for this night. I went into the washroom and took a warm shower before putting on my pyjama. I got out and joined Sans into our room. He was already in the bed, waiting for me to come. Once I layed down, Sans spoon with me, him being the bigger one. He wrapped his arms around my waist, pulling me closer to his chest and burying his face into the crook of my neck. He pecked my cheek.

Sans- I love you, sweetheart.

You- Me too.... punny guy.

Sans- What that nickname! I didn't expected ya to be the humerus type.

You- Wow! Seriously, what was that? Hope you didn't said that to any other people, 'cause that explain the fact that you're bonely.

Sans- Ok, fine. Ya got me 'ere. But I can get ya too.

You- How? You're gonna throw me a mustard bo-

He. Licked. My. Neck.
....
....
And. I. fucking. Moaned!
Like what the fuck! He chuckled a bit and did it again. I shiver running down my spine.

You- S-sans! Stop that!

Sans- Fine....

(The whole conversation was in a whisper)

He chuckled and stopped. I sigh in relief and held his hand. Pecking him on his cheekbone and then closed my eyes. I drifted off to sleep with a smile plastered on my face.
~next day~
The next morning, when I opened my eyes, I didn't wanted to get up so I just stayed there in the hold of Sans. I turned around so I'd be facing him and wrapped my arms and legs around him. He woke up and I kissed him, he was confused at first, but soon  melted into it. We end the kiss, still staying in the comfy bed. Today was the day. Me and Sans were going to the Alphys's lab to test creating the soul. The king had informed Alphys that he gave us the right to come there whenever we wanted. We had four days to create something. Complete or not, if it's something that's working, the king would give us the time to do it. If we had nothing, the option of letting the strongest monster take the souls would be the principal option. Once I gained the motivation to get up, I let go of Sans, pecking him on the lips before standing up and dressed myself up. I took my clothes and went into the washroom. I took a black and (f/c) stripped long-sleeved shirt with blue jeans and (f/c) socks. I fixed my (h/l) (h/c) hair in a ponytail and went downstairs. Sans was already there with Papyrus, eating scrambled eggs, toasts and orange juice. Sans wore only a red turtleneck with black basketball shorts and had his mustard bottle as usual beside his juice. A plate was already made for me as I sat down. I thanked Papyrus for the breakfast and started to eat. His eggs were a bit burnt since it was his first time. Yeah, he never cooked anything other then lasagna until I arrived. I quickly ate and went to the door, putting on small leather boots with a zipper on the side. Sans joined me soon and putted on his red sneakers. He knotted the shoelaces and putted on his coat. I putted my black hoodie and opened the door, saying goodbye to Papyrus. Sans shortcut us directly in front of the main lab and we entered in, going to the elevator. We entered the elevator, pressing the button to go to the true lab. I took a shaky breath, remembering what happened down there. Sans probably noticed my stressed face because he grabbed my hand and gave it a gentle squeeze. I looked at me and he pulled me in a hug. The elevator's doors opened slowly and we got out of it.

Let's do this!

Sorry, I'm currently writing another story at the same time. I just want it to be finish before publishing it, that way, I'll focus more on this one. Don't forget to like! (And subscribe OwO)