Undertale - Sans x Reader (Oneshots)

Sans x Dying!Reader

Y/N was 28 years old now and it had been many years since they were out of the underground. Sans was good friends with Y/N but about a year ago he started to fall for the human. But they had been acting funny lately but not the kind he could crack a joke about...no it was very off like they are sick or something. Y/N had went to the doctor, they told no one. But he followed them, once he got there they came out in tears as his eyes widened at that. Why? Why are you crying?

It had been a week since then, him and Y/N are walking to the store. "So...um kid.." He was cut off right away. "I'm not a kid Sans, I wasn't a kid when I meet you either." They were right. Y/N was 19 when they fell in the underground, the first ever well...Non Kid to fall into the underground but they all still tired to kill them anyway, they said 7 human souls. "Haha yeah your right but as a monster am a lot older then you still so your a shrimp to me." They pouted punching lighting. "What did you wanna ask?" They smiled a bit. "Well, I was wondering. Why did you go to the doctor a week ago?" They stopped walking, eye wide as they stared at sans. "What kid?" He stopped looking behind him and turning around slightly. "How did you know that?" They asked looking almost a little angry at that. "Ahh well I was worried with how you were acting lately. So I .....kind of followed you." They looked up, yup angry indeed. "What you weren't tell me anything kiddo so yeah I followed you." He somewhat said a little angry as well.

The kid- err Y/N sighed loudly as they still looked pretty mad, "I know you mean well but what I do in my time is private. You had no right to follow me like that." They pointed at him. This made Sans even more angry, he did it cause they wouldn't tell him anything and are keeping something...something big from him. "I had no right? I had no right!? I did cause I care about you and wanna know what is happening to you! I get it Y/N, I really do but this is not something you can hide from me whatever it is. It really upset you when you came out the other day, please Y/N tell me what is happening to ya?" He became less mad the more he said it, he was trying to comfort them in a way. "How can I tell you? I reset so many times on you guys cause I got mad and almost....I can't do this anymore...Sans I care about you too. But honestly this is for the best for all of us in the end. I need to be punished for ever thinking those thoughts." They had tears in their eyes and Sans walked up to them wiping them away with a boney finger. "You should never think that kid, what would the other say if they heard you right now. Look I told ya I forgive you for thinking that, am happy you never gave in to the voices in your head. But I need ya to trust that I will be here for you. Come on kid? Y/N tell me, I won't get mad." He smiled a lazy smile and they smiled back but frowned soon after. "*sigh* I'm.....oh god..*sob* Sans. I'm...dying." They burst out crying at this point and Sans stood shocked with blank eye sockets. "What?" He asked in disbelief. "I went the other day because I was coughing up blood. And I haven't been able to keep anything down." He had noticed this, the kid was getting skinnier with the passing days. "I have stomach cancer Sans...I only have a year till..." He looked away now he couldn't no this couldn't be happening...not to them anyone but them! "Reset.." He said quietly. "*sniff* W-What?.." "I said Reset. A full Reset." It was the only way he knew how the kid could be saved. "But Sans I can't and even if I could there is no guarantee that I won't get it again and then we would be going over this over and over again. I don't want that for you Sans...any of you." They cried. "Then we can ask Alphys to look at you, we can explain to her the whole thing! And we can't find anything then I'll remember all we found and start off of that until we get it right!" He yelled. "Sans this is crazy! That's crazy! This will drive you to madness, why are you even trying!" "Because I love you!" He gasped along with them. "You...mean that..how Sans?" They asked blushing slightly. "I mean like this." He kissed them softly as a monster with no lips can. "I can't bare the thought of you not being here Y/N. Please I know what might happen to me....but at least at the end of it all..I can get you back, and keep falling in love with you all over again." He laughed as they giggled at that. "I don't wanna leave you Sans, ever. If this is what you really want then I'll try, for you." They kissed him back. "Also we will remember each other so how can we fall in love again?" He chuckled. "Well hey I bet we can, your more beautiful then anything I have ever seen. So you will blow me away everytime, reminding me what am fighting for again and again." He hugged them as they hugged back.

They sighed. "Come on, Y/N. Let's go back together." They smiled and nod. "Okay.." They were back at the ruins redoing everything till getting to the gate. A tree branch broke and they smiled. "Hey, don't you know how to greet a new pal. Turn around and shake my hand." He said again and Y/N jumped into his arms and he caught them like he was planning on them doing it. "Hi, Sans." They laughed. "Nice to have ya back kiddo. Welcome home." 

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Been awhile since I made an undertale x reader so I wanted to finish this one I made months ago. I hope it came out okay and that you enjoy. I wanna do more other stuff and not just tmnt so if I don't post anything from tmnt for a bit, its cause am working on other things for now. thanks for reading.

Stories by MushroomFiction.