A whole new experience (Sans x Reader)

Undyne

While you and Sans walk back to his house through the cave and Snowdin. A lot of people look at you and Sans holding hands. Most of them smile at you when they see you two, some of them nod in approval. It makes you feel better about the relationship you and Sans have. Even though you don't even know what kind of relationship this is. As more people smile at you, you can feel your cheeks getting more red by the second. You look to your left to see Sans' face. As you look at him you can see his cheekbones getting a slight blue color as well. it pleases you to see him like that. Because it must mean he feels the same way.

The second you and Sans enter his house Papyrus runs up to you. ''SANS, (Y/N), I HAVE SOME GREAT NEWS. UNDYNE WANTS TO MEET THE HUMAN. ISN'T THAT GREAT?!'' Papyrus yells in excitement. You feel your heart sink into your shoes. "U...Undyne...isn't that the...the lady who wanted to...to take my...my soul.'' You stutter while you feel all color drain from your face. You can feel Sans squeezing your hand. Then suddenly he let's go of your hand, grabs Papyrus' hand and pulls him upstairs into Papyrus' room. You can hear their voices coming from upstairs. Though you can't hear what they are saying, it sounds like they're fighting. You decide to creep closer to the door of Papyrus' bedroom to hear what they are saying. "Stop denying it Pap, I know you told Undyne about (Y/N).'' You hear Sans say with an angry tone in his voice. ''WELL...MAYBE IT WAS ME, BUT THAT'S OKAY RIGHT? UNDYNE ONLY WANTS TO MEET THE HUMAN. THEY CAN BECOME FRIEND LIKE UNDYNE AND FRISK.'' You hear Papyrus say. You don't know who Frisk is. He might be the other human that fell down here before you that you heard some things about. But that isn't really your main problem right now. ''If she is going to try to take (Y/N)'s soul, and she succeeds...just know that I'll never forgive you.'' You hear Sans say in a threatening voice. You can hear footsteps coming closer to the door. You want to move, to run downstairs. But you stay right where you are. Then Sans opens the door. In his left eye you see a bright blue color lighting up. You both look at each other for a few second. then you decide to speak up. ''I want to meet Undyne.'' You say looking determined. "I will try to convince her that I am friend. Not a foe.'' Papyrus sticks his head out of his room looking at you with a big smile on his face. You smile back at him. ''SEE SANS, EVEN THE HUMAN KNOWS THAT UNDYNE WILL BE GOOD FOR HER.'' Both you and Papyrus are smiling, but when you look at Sans your smile disappears immediately. On his face is a strange look. It's somewhere in between worry and anger. His left eye still showing a bright blue light. it's scaring you. Then, out of nowhere, Sans walks down the stairs. A few seconds later you hear the front door closing with a loud bang. You look at Papyrus worried. "Don't worry human. Sans will...change his mind...he just...needs some time cooling down...let's...let's go to Undyne okay?'' You can't help but notice that his usual cheerful voice disappeared. ''Yeah...let's go meet Undyne.'' You say. You follow Papyrus outside.

The entire walk to Undyne's house you can't help but think about Sans. That look on his face looked strange. You truly hope Sans isn't mad at you. Sooner then you thought you and Papyrus arrive at Undyne's house. ''THIS IS IT HUMAN, UNDYNE'S HOUSE.'' Papyrus knocks on the door. you notice has his standard cheerful tone in his voice again. It makes you happy. It must mean that Sans will be alright. A few seconds later the door slowly opens. A fish like lady with blue scales all over her body and an eye patch over her left eye stands in the doorway. This must be Undyne. ''Is this the human you talked about Papyrus?'' Undyne says. Papyrus nods excited. ''YES THIS IS HER UNDYNE. ISN'T SHE COOL.'' Papyrus says as he pushes you forward to Undyne. "Excellent work Papyrus.'' Undyne says as a devious grin appears on her face. At the same time an illuminating blue spear appears in her hand. ''UNDYNE...WHA...WHAT ARE YOU DOING. YOU SAID YOU ONLY WANTED TO MEET HER.'' Papyrus stutters. ''Why do you even care about her Papyrus. This isn't Frisk. This is perfect, now all of us can leave together with frisk.'' Undyne raises her hand and aims the spear at your face. ''YOU CAN'T HURT HER UNDYNE. SHE IS INNOCENT. AND SANS LIKES HER SO HE WILL GET MAD AND...'' ''You talk too much Papyrus.'' "BU...BUT UNDYNE...'' "Please, U...Undyne...I don't...don't want t-t-to hurt a-a-anyone.'' You stutter as you look at Undyne with fear in your eyes. ''How could i know for sure?'' Undyne asks you. She still sounds kind of mad but she lowers her spear. ''I-I-I really d-do-don't want to hurt anyone. I never killed a-anyone. I-I-I promise.'' You stutter while looking at the spear in her hand aiming lower and lower. ''SHE IS A NICE HUMAN UNDYNE I, THE GREAT PAPYRUS, AM SURE OF IT. AND I AM ALWAYS RIGHT.'' Papyrus says. After a few seconds of tension. Undyne lets the spear in her hand disappear. ''Ugh...you and that stupid little human made me soft.'' Undyne says as she steps aside so you and Papyrus can enter her house. Without a doubt Papyrus walks past Undyne into her living room. You follow him closely. You Papyrus and Undyne sit together at the dinner table. 

After about an hour of awkward conversation you, Papyrus and Undyne start to feel e bit more comfortable around each other. And the awkward conversation turns into a more pleasant one. You talk about the royal guard, how pretty the waterfalls are, some of Undyne's favorite fighting techniques and much more. Then, all of a sudden, Papyrus stands up. ''I JUST REMEMBERED I HAVE TO GO DO SOMETHING.'' Papyrus says. He looks at you and Undyne for a second. Then he runs away from the table and jumps out of the window. ''Not again.'' Undyne mutters. You chuckle at Papyrus' silliness. "So, (Y/N), I have heard some things about you. You and Sans to be exact.'' She smiles at you as you feel your cheeks getting a slight red color. ''So, is it true? Are you two a couple?'' She asks as she bows over the table to get closer to you. ''I...I-I-I don't know...I kind of hope so, but I'm not sure.'' You say. You feel your cheeks getting red again. You decide to change the topic before your head will get as red as a tomato. ''How is your love life going Undyne?'' You ask quickly. ''Oh...uhm...well...kind of good I think.'' Undyne says as she sits back down in her chair. ''Do you have a significant other?'' You ask. ''Yeah, and she's really cool and cute and stuff! You know you should really meet her! Let's go to her lab together tomorrow, okay?!'' Undyne yells at you with a voice filled with excitement. ''Yeah, sure, sounds like fun you say.'' As you smile at Undyne. All of a sudden you hear knock on the door. When Undyne opens the door you see Papyrus standing in the doorway. ''IT IS GETTING LATE (Y/N). WE SHOULD GO HOME ALRIGHT. I HOPE YOU TWO HAVE HAD FUN CHATTING WITH EACH OTHER.'' Papyrus yells as you walk over to the door. ''Yes, I suppose it is getting late. We should go home. It was fun meeting you Undyne.'' You say as you shake her hand. "Papyrus was right human. You are pretty cool.'' Undyne says as she closes the door behind you and Papyrus. You smile and wave at her. She waves back.

When you and Papyrus get to the home of the two skeletons all the lights are already off. ''I SUPPOSE SANS IS ALREADY ASLEEP. WE SHOULD SLEEP TOO. GOODNIGHT HUMAN.'' Papyrus says. as he gives you a short goodnight hug and then runs up the stairs to his room. You can hear his door closing behind you. Without thinking about it any longer you crawl into bed.

About half an hour later you still couldn't sleep. You were still thinking about Sans. Would he be okay. You sure hope so. Then you hear footsteps coming down the stairs. You open one of your eyes slightly to see who it is. You see the silhouette of Sans standing at the bottom of the stairs. He seems to be staring right at you. You don't know what he means with it. Maybe he is still mad at you. But than why would he come all the way down stairs to look at you. He sits at the bottom of those stairs for several minutes. You do your best to pretend like you're asleep. When he finally goes back upstairs you are so exhausted from the effort to remain completely still for so long, that you fall asleep almost immediately as soon as Sans walked back up those stairs.