All Undertale AUs x reader One-Shots

I thought you loved me UT!Sans x reader

Today you were at home doing chores and watching tv. "I'm bored" you sigh you look through the window bored. "I wonder when sans coming home? I should call him" you pull your phone out and dial sans number. "Hello?" It was sans voice "Hi sans I was wondering when you coming home?" Sans was silent for 5 seconds "I'm not coming home today (y/n) I have a lot of work to do so I have to stay for the night" sans said making you sad "oh..okay will you be home tomorrow then?" You asked "yeah I'll be home tomorrow" sans said silently sighing "oh that's great to hear! Can't wait to see you sans I love you" you said a bit happy he's coming home tomorrow "......yeah love you too" sans then hangs up. You hang up as well it was getting late so you went to sleep.

~The next day~

You woke up and saw sans. You got up from your bed and ran to sans and tackle hugs him. "Sans I missed you sooooo much" you said happily but for some reason sans jacket didn't smell like ketchup like it usually does it smelled like perfume. "Heh I missed you too (y/n)" sans said you let go of sans "hey I got to go somewhere for a bit I'll see you later" you said as you kissed sans on the cheek. You walked out of the house and went to (f/n) house. As you got to (f/n) place you knocked on her door. She opens and smiles "Hi (y/n) how are you?" You walk into her house "I'm good I guess but I feel like my sans is hiding something from me" you said as you sit on a chair "How do you know?" (F/n) asked "well his jacket didn't smell like ketchup like it usually does it mostly smelled like perfume" (f/n) thinks for a moment "why don't we spy him for a while" you were a bit shock but agreed "let's hope he's still home" you nod as you and (f/n) gets out of (f/n) house to yours

~at (y/n) house~

When you two arrived at your house you were about to walk in but (f/n) stopped you "hey I got a message from my boss and he said it really important so I got to leave. Sorry" (f/n) said with a sorry expression "it's fine Ill see you later" you smiled she nods and left. You sighed as you walk in. You look around and didn't see sans anywhere down stairs so you went up stairs to see if sans were up there. As you continue walking you heard noise coming from you and sans bedroom. You peeked from the crack door your eyes widen as you see sans kisses Toriel. You open the door wide making Toriel and sans look at your way with wide eyes. "(Y-y/n) this isn't what it looks like" sans said with a nervous tone "isn't what it looks like? THIS IS WHAT IT LOOKS LIKE!?
" you said yelling with tears forming in your eyes "Sans why are you doing this?! " sans looking away not wanting to have any eye contact with you "i did it because I like someone else" sans looked up and saw a hurt and sad expression. You step back about to run but you weren't gonna run just yet " I...I thought you loved me sans" you looked down with tears streaming out your eyes "heh I'm so stupid...." You looked up with a hurt smiling expression "I bet you never even loved me in the beginning" sans eyes widen then looks away "I'm sorry" suddenly you stop crying "why are you sorry for? I should be the one saying sorry" you smiled "I'm sorry that I wasn't enough for you" you went and got all your stuff and left. Toriel looks at you with a apology face "I didn't mean to..." You went up to her "it's okay...please do me a favor... Make sans happy for me" you said as you start walking away.

~1 month later this is also gonna be sans pov~

All of (y/n) stuff was out if my house. Everything was quiet and nearly empty now she was gone it hurt me seeing her leave with all of her stuff. I regretted falling in love with Toriel cuz now I'm with her I can't see (y/n) welcoming smile that alway warm up my heart and my soul. I don't even know how I fell for Toriel. A month has passed and I already miss (y/n) so much. I want to see (y/n) again and have her back. She was my little world but now I can't go back now it was too late I had so many chances but denied it now I have to face the consequences.

Welp hope you like that heart breaking story. Now I'm just gonna go to a corner and cry. T^T