I'm not alone... (Underfell Sans X Reader)

"S-Sans?" You whispered.  "I am so sorry!"  You blushed in embarrassment.  "....Look, it's fine, and sorry for being such an asshole, but....where'd you get that bruise?" He asked, going straightforward.  You widened your eyes in surprise and hid it with your hand.  "I-uhh..." You trailed off.  "My dad."  You finally sighed.  "He was a sick, horrible man. And if I remember correctly, he did the same to my baby brother, B/N.  I'm so glad this place is much better though..."  Sans snickered.  "What good do you see in the Underground?" "Well, there's Papyrus, and there's you...." You realized what you just said and felt your face burning.  You covered your face with both hands, hiding he blush.  He chuckled and uncovered your hands, then pulled you into a tight embrace.  "Just--know you're safe here, kid." He whispered.  You could have sworn you saw a red blush creep across his face, but he got off the bed and turned towards the door.  You guessed the door was no longer locked, so you followed him.  You both climbed down the stairs, greeting Papyrus.  "MORNING HUMAN, SANS." You nodded. "Morning, Papyrus!"  "I SUPPOSE YOU AND SANS ARE OKAY WITH EACH OTHER NOW?" He asked.  You looked over at Sans, not knowing what to say.  "Sure, Pap." Sans said.  "WELL GOOD.  I MADE THE TWO OF YOU BREAKFAST!"

~Le Time Skip~

You and Sans sat on the couch after breakfast.  Papyrus had to go training with someone named Alphys.  You sat a couple cushions way from him, thinking he might want some space after what happened recently.  You looked at the screen, your head resting on the palm of your hand.  Sans looked at you, and you looked back. He patted the cushion next to him, inviting you sit there.  You scooted over to him, feeling a bit uncomfortable.  One moment he wants to kill you, the other he wants you to stay close.  He rested his arm around your shoulders, which made your face burn.  He acted as if nothing was really happening.  How??  You had no idea. You scooted a little closer to him and yawned.  He chuckled and let you rest your head on his shoulder.  You haven't been this happy in a while.  ....Have you ever been this happy before?  You couldn't remember.

You opened your eyes to see Sans resting his head on yours'.  You smiled, guessing you just zoned out.  But...you were sitting on his lap.  You blushed so hard you looked like a cherry.        You wriggled around a little bit, wanting to give him some space, but his grip was tight.  You sighed and rested your head on his chest, but realized he moved.  You looked back up to see him staring right back at you.  You squeaked and jumped off.  "Oh my gosh! Sans, I'm so sorry--" "Kid, it's fine! Stop apologizing already!"  He laughed.  You put your arm behind your neck, embarrassed. "Why're you going so soft on me...?" You asked. He gave you a confused look and waited for a while before answering. "Kid, you-you're different than the others. You were the only one who showed any kind of mercy to us. You've gone through so much and....well....I shouldn't have treated you like that before." He said. You could tell he meant every single word. "Gee, Sans...." You whispered, not knowing what to say. Sans started to move closer to you. He lifted your chin with a finger so you looked at him in the eyes, and he kissed you. You gasped in surprise, but relaxed. You kissed back, wrapping your arms around his neck. You pulled back first, blushing harder than ever. This time Sans pulled back into the kiss, his arms snaking around your waist. He pulled you back onto the couch, and loomed over you. Now his arms were at your sides. He lowered himself just to where he could nibble at your neck. You gasped in surprise, but was too frozen to do anything. "S--Sa--n..." You choked out. You tried to lift your hands, but nothing happened. Sans lifted up to see your face, red, hot and sweaty. She was gasping for breath.  She really did look cute like this, Sans thought.  "Y/N..." He whispered into your ear, making you shiver a bit. You didn't reply, but looked back at him. He kissed your forehead and hugged you to where your chin was resting on his shoulder. "Never leave me..." He whispered.