Undertale {Sans X Reader}

He Now Knows

~ Sans's POV ~

When I was fighting y/n, I flung her to the ground, the tracks covered in her blood.

serves you right, you dirty brother killer, I thought.

I was standing over her, looking down at her body that was in horrible condition.

"your way weaker than the others, since i can tell your DETERMINATION is unstable. which makes it easier for me to do this." I said to her.

We both heard footsteps, quick and heavy, like they were on the run from something. I didn't need a monster to think I was the killer here, so I snapped my fingers and both my Gaster Blasters disappeared. I looked to see who was coming, and y/n got up and ran towards the Waterfall entrance.

"get back here!" I yelled, but she kept running. I sighed and saw Toriel coming towards me. She was out of breath.

"Sorry...I'm late...Sans..." She stood up straight and looked around after catching her breath. "Is y/n here yet? I can't wait to see my child!" She sounded so excited.

"no," I then said, feeling horrible for the things I did to her, but not super horrible. I was still super angry at her. "she may still be out with pap." It pained me to say Paps name, but I got through it.

"Alright. I'll be inside if you need me." Toriel then gained a happy look on her face. "Oo~! I can't wait to see y/n again! It's been weeks since I last saw her! I hope she gets really surprised!" She then leaned down to my hight. "This is a grand idea Sans, and I bet she'll love it." Toriel gave me a hug then went to the house.

My laziness kicked in, so I was going to teleported to where y/n was. I'd love to finish her off when I find her, but it'll destroy Toriel, and I don't want anyone else in pain.

I arrived at the Waterfall entrance and started looking for y/n. Then I heard singing.

"Go ahead and just hit me since your able,

"We both know my DETERMINATION is unstable,

"I'm not even mad because I keep on dieing,

"But I don't even know why I'm trying.

"I'm made o-o-of, lo-o-o-o-ove,

"lo-o-o-o-ove.

"And I'm not stronger than you..."

She then went and lied on the ground. I just watched her. Y/n wasn't going to change my mind about her killing my brother over a song.

I left her there and started heading back home. Maybe I could convince Toriel that something happened to y/n and that she'd never come back. I'll think about it later.

Then, I heard an all to familiar voice.

"Y/N! HUMAN! DID YOU MAKE IT BACK HOME, OR ARE YOU LOST, BECAUSE THE GREAT PAPYRUS CAN HELP YOU!"

"p-pap." I stuttered at a loss for words.

I ran out of the Waterfall entrance to see Papyrus looking around for something...or more like someone.

"papyrus!" I yelled as I ran to him with tears in my eyes and probably looking dumb. Papyrus keeled down to my height and accepted the hug that I gave him when I reached him.

"WHAT'S WRONG SANS?" He asked, pulling away. "AND HAVE YOU SEEN THE HUMAN?"

"no, i thought you both were still at undyne's. tibia homest, i thought you were dead, since you never called or texted me."