(Sans POV)
I was really tired and I eventually fell asleep. "SANS YOU IDIOT! YOU FELL ASLEEP AGAIN?!" I open an eye to see Underfell Papyrus. 'What is he doing here?' "Um hey bud I think yo-" He then grabbed me by my arms and pulled me out from behind my station, bending me over "H-hey bud, let go!" I squirmed and he put a collar on me along with a leash. "SHUT UP, YOU LITTLE SHIT!" He yelled as he teared off my clothes. Fell spread my legs apart and entered in me, all of him. I yelled in pain and screamed for my Papyrus. He thrusted into me harshly and I kept screaming and yelling. Papyrus came running towards us and knocked Fell down before grabbing me, and running to our home. Once we got inside he locked the front door, and hugged me tightly "You okay Sans?" His voice was calm, gentle, and soothing. I hugged back and nodded. He kissed my head and smiled warmly. God I love his smile, and his voice, and everything about him. He gently picked me up like a baby, and rocked me. I blushed. "Papyrus." He kissed my head. "Shh, Sans just let me take care of you." I was getting tired and dozed off.

(Papyrus POV)
I smiled at how cute he was. "I love you Sans." I caressed his skull, before kissing it. 'So cute' I thought and I tip-toed upstairs being as quiet as can be, not to wake him up. I went into my room and gently laid him down on my bed. I noticed he still had the collar and leash on. I put my hand under his skull, lifting it and took off the leash and collar, before gently laying his head back down. I kissed his forehead then turned off the light and whispered. "I love you my cute little Sansy." After that I left the room, shutting the door silently.

~Time skip~

(Sans POV)
I woke up in Papyrus' bed a bit confused but awake. I stretched and rubbed my eyes. I got out of the bed and walked out of the room. The air was filled with the scent of spaghetti. I went into the kitchen and saw Papyrus. "Hey Papyrus." I greeted, and Papyrus turned his attention towards me. "Hello Sans!" He smiled brightly. I went over to him and he kissed my head. I smiled and nuzzled him. He soon finished cooking and put the food on two plates. He then picked me up and put me on the counter top. "Bro? What're you doing?" He spun the fork in the spaghetti then held up the fork in front of my mouth. "Open up Sans." I opened my mouth and he put the spaghetti in my mouth. I ate it and swallowed. I was then picked up and brought to the living room. We sat down and Papyrus had his arms wrapped around my waist, and he kissed my head. I chuckled softly and he held me close. I blushed but liked the warmth and love from him. I nuzzled him.  He rubbed my skull gently. He continued this until I fell asleep.

(Papyrus POV)
I smiled softly and remembered that Sans will be turning 10 tomorrow. I sighed but kept caressing his skull. I will take care of him even if this de-aging thing had affected him. I stood up cradling him in my arms, and swayed side to side. "Sleep well Sans, my little brother." I kissed his head and took him to my room, so he can sleep.

~The next day~

(Sans POV)
I woke up to Papyrus' sleeping next to me. I carefully got out of the bed and went downstairs to the kitchen. I went in the fridge and grabbed the ketchup, opening it. I started to drink the ketchup until I heard someone come downstairs. I instantly put the ketchup back but it was to late. Papyrus caught me. "Sans were you drinking ketchup?" He asked "No." I lied but he saw through it, he put a finger in his mouth then took it out before wiping the ketchup off my cheek. "Not drinking it hmm?" He smirked and cleaned his finger. He then picked me up "No drinking ketchup before breakfast mister." He said and I nodded. "Good." I was put on the counter and he began cooking. I watched him cook, and I layed on the counter. My eyes began to wander around the room. I looked at the front door. "Big brother?" I looked back at him and realized I called him 'big brother'. "Yes Sans?" He replied.