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

Emergency

Sans pov

I woke up slowly, feeling a bit dizzy. Ugh, my head.... I sat up carefully and looked around, I was on the couch of the living room.... Wait... how did I arrived here? I remember... being in the lab... then all black... pain... (Y/n)....
Wait, PAIN?! I looked at my arms and legs, they were covered in bandages and my turtleneck had dust on it, along with a bit of dried blood. I stood up and stumbled upstairs to my room. I opened the door and found Papyrus, beside my bed. (Y/n) was there, unconscious.

Papyrus- SANS? WHAT ARE YOU DOING, YOU SHOULD BE RESTING!!

Sans- What happened?! Why is she like that?!

Papyrus- YOU'RE THE ONE WHO SHOULD KNOW, SHE ENTERED THE HOUSE WITH YOU ON HER BACK, SHE JUST HAD THE TIME TO PUT YOU ON THE COUCH THAT SHE COLLAPSED!!

Sans- Shit, she said she was ok!! Why does she always lie!!

Papyrus- SHE SAVED YOUR FUCKING LIFE AND YOU COMPLAIN ABOUT HER LYING?!

Sans- No, it's not tha-

Papyrus- SHUT UP SANS!! JUST LEAVE, I NEED TO TREAT HER, IF YOU WANT TO BE USEFUL, GO BUY SOME HEALING BUNS AT THE SHOP.

I grunted in response, but didn't complained since her life was on the line. She had already lost some fingers and toes because of Alphys, but now she had a giant hole in the cheek and multiple other wounds on her body. I went downstairs, putted on my coat and teleported in front of the shop. I felt a bit dizzy this time, probably  because I lost energy and HP. I entered the small shop and walked to the counter.

Shopkeeper- Ah, Sans! What brings you here, did you missed me?~

Sans- I need two healing buns.

Shopkeeper- You're no fun Sansy~ how about I give you one free for one kiss?

Sans- No, just give them to me, here.

I putted ten G on the counter and waited for her. She sighed loudly and finally went to the back to take the buns. She came back with a small paper bag in her furry hands. I took the bag and teleported home. I appeared in front of the door, but visibly, I wasn't the only one. A bunch of monsters were there, each and everyone of them were armed. I tried to subtly make my way toward the door, but maby I should teleport inside instead? Suddenly, I heard the sound of shattering glass and saw some bones impale the intruder.

Sans- Shit, I gotta do a cleanup...

For info, when I say a "cleanup" when there monsters, that means a massive attack. Like.... A gaster blaster.

I spawned two small gaster blasters and yelled -" GET THE FUCK AWAY, SANS IS HERE!!"- then I fired. A couple of monsters escaped the blasters by throwing themselves on the ground or by using magical platform to be above the laser, but basically the 3/4 died in a blink of an eye. I then proceeded to enter the house casually. Papyrus looked at me with his shoked face.

Papyrus- SANS, WHAT WAS THAT...

Sans- Nothing boss, just me making my way through.

I then quickly went upstairs and entered my room. I looked down to  (y/n)'s unconscious form on my bed. I opened her mouth and used a bit of my magic to make her swallow the small pieces of healing bun I was giving her. After a couple of minutes, the magic started it's effect and a small green glow was emitting from (y/n)'s wounds. The hole in her cheek started to close slowly and the cuts disappeared too. Every bleeding stopped and her breathing became more stable, I let out a sigh of relief as she was almost completely fine again. She still had a small hole in her cheek, but she seemed in less pain then earlier. I let out a sigh of relief and started to play with her soft (h/c) hair. I stayed like that a couple of minutes until she finally cracked her eyes open. I smiled at her softly as she slowly smiled back, she sat up on the bed and took a look around.