Undertale: One Shots! [REQUESTS INFO ON LAST CHAPTER]

Science Sans X Underfell Sans

((Let's see what I can do for this one! Sorry if it ends up crappy, I don't know much about Science Sans! Mature language included! You've been warned))

((SCIENCE SANS'S POV))

Gaster kept pestering me about this invention he had made. It wasn't all that big of a deal, until he made it one. He invented a machine that allowed us to bring in people from an Alternative Universe to stay with us for as long as we wanted. Apparently, there were an astronomical amount of Alternative Universes that had me in it.

Some Alternative Universes only had me in it. Quite shocking, to say the least. Since there were countless versions of me, Gaster made sure to find the perfect one that would be sure to annoy the hell out of me. He told me to work with it staying around the lab. I said his idea was ridiculous. He called his idea fun.

Naturally, I denied the challenge. But then, he promised me my very own chance at using Gaster blasters. Something I had wanted to own in possession for ages. So I leaped at my opportunity.

"Ready?"
"I guess."
I saw a blur of red enter the room. Then, the blur shifted into a body. I instantly recognized what I was looking at. Me. Only with a darker set of clothing consisting of black and red, one red eye, and one golden tooth.

"This one comes from an Alternative Universe where everyone who is cruel, is nice, and everyone who is nice, is cruel." Gaster explained, adjusting his glasses.

The other me stumbled, then looked back and forth, and then looked at me. "...what the hell?!" He scoffed in shock. "Your here for a little experiment. I promise you shall be rightfully returned to your home asap." Gaster reassured and patted my other self's head.

"Hey hey, no touching!" The other me protested and pointed a finger threateningly at Gaster. "I'm warning you! I don't give two craps about this whole "experiment" thingy! I didn't agree to this!" Gaster only chuckled and shoved him off into another room, along with me. "Have fun you two~!"

"WAIT N-!"
SLAM!
And just like that, we were left to ourselves. I decided it would be best to ignore him and work on my current project. "Hey! Don't just start doing your little science thing! Help me get outta here!" He pestered and pulled at my arm. I didn't budge, but I must admit, he was pretty strong.

Probably stronger than me. The whole afternoon he spent drowning my thoughts out with his request to get out of here. I tried my best to continue on with my work while ignoring him. "Let me outta heeeeere..."
"No."
"Papy is going to SLAUGHTER ME!"
"Who?"
"Papy!"
"Papyrus?"
"That's what I said!"
I sighed and tried to pour in a chemical into a glass container. I concentrated and blocked out any distractions, narrowing my eyes until...almost there...
Wait, is it just me, or is the other me awfully-

"BOO!" The other me shouted and I jumped. "Ghh-!" I cried out and dropped the chemical. It spilled into the glass container and...

POW!

"Hm...? What is it Sans?" Gaster asked, answering the door to his office. I could hear the idiot laughing himself to death in the background. My face was covered with blue powder due to the exploding of the chemicals.

"I can't take this anymore I need him OUT." I stated through gritted teeth. Gaster raised an eyebrow. "Already? Nonsense. You can do it. It's only been six hours." Gaster stated and patted my head.

"Ughhhhh....you just love to see me in pain, don't you..." I mumbled and he laughed. I stormed back to my room and cleaned off the powder. The other me wrapped his hands around my waist and rested his face on my shoulder. "Aw, c'mon, can't you take a joke~?" He teased. I proceeded to ignore him and clean up my office...

((UNDERFELL SANS'S POV))

It was the next day. I was opening up more to this guy. He was the best person to mess around with. Despite our similar looks, there were still some faces he would make that would make me laugh. I flung my eggs from breakfast at him, and drank some of his orange juice. Every time he would refill it, I would empty it out by drinking it again.

He got really mad when he figured out it was me behind the prank. I spun around in his science chair. "Don't you do anything other than work, sweetheart?" I teased and he sighed. "Don't call me sweetheart. If I were you, I'd be wouldn't be shocked if I didn't get fed any lunch. I usually only eat breakfast, you know."

That shut me up real fast. "Wait, you can't let me starve to death, honey!" I cried out, and though I was serious, I kept the sweetheart and honey shtick going.

"Don't call me honey!" He barked back at me. I chuckled and continued to spin around. I was getting super bored, so I gradually kept spinning myself faster and faster until the chair suddenly fell over. "Woah woah wooooah!!!" I shouted as I fell over and landed head first onto the ground.

This caught his attention. My vision was blurry and I tried to stand up. I saw him rush over to me, and helped me lay down on his creepy doctor bed. "Ugh...someone give me an aspirin...cause your really giving me a headache..." He mumbled in annoyance. I froze.

"Did you just make a joke?!" I asked and began to laugh. "Wait! Don't laugh! It will only increase your headache!" He said and covered my mouth. Man, he was really worked for a guy who just met me.

((SCIENCE SANS'S POV))

The next day, my other self woke up with a sore body. He was hurting all over, I felt really bad. I gave him something to hopefully help him not feel as much pain. "My dearest, won't you spare me a kiss to help me bare through this unbearable pain~?" He asked in his best actor voice.

My face flushed a dark blue. "Your spewing out nonsense now just to make me get flustered, aren't you..." I mumbled in annoyance. He smirked and took the advantage to plant a kiss on my cheek. I looked at him in shock. "What was that nonsense you were speaking of, darling?" He asked me teasingly.

I frowned and he chuckled. I wanted to just this once, wipe that snotty grin off of his face. Just once. Just this once. So I prepared myself and dove in, kissing him right on the lips/teeth (since he's a skeleton you know). I pulled away to see his face turn into a firework show of red.

It was my turn to chuckle at his flustered expression. "Was that enough proof to show how fake that last kiss was, honey?" I asked in my best acting voice, standing up and walking to my desk.

He grabbed my hand before I could leave and grinned again. "...I think you can skip work today to spend sometime with me, sweetheart~!" He said and pulled me back onto the doctor bed.

The rest of the time we spent telling each other jokes that we had worked up, chasing each other around the house, and just cuddling while watching a movie. It was the most fun I had ever since everyone I knew had joined up for a sleepover.

Five days later

"Hello?" I heard Gaster ask. "Hey! How's work?" I asked with a soft smile. He shrugged. "Taking a while, but good! It's going a lot faster with your help, though." Gaster said with a grin. I chuckled and heard the microwave beep. I rushed over and took out three hot chocolates.

I handed one to Gaster and one to my sweetheart. "Thanks." He said and kissed me on the cheek. My cheeks tinted a light blue and I nodded. "No problem." I said and winked. "Be careful, it's still hot." I warned Gaster and my darling.

"So, I guess you win. You two got along so much better than I expected you would." Gaster said. I shrugged. "Opposites attract." He chuckled and nodded. "I suppose your right on that. You sure you don't want to go back to your Universe?" Gaster asked my dearest.

"I'll understand if you do...." I mumbled and he shook his head. "No way. Maybe I'll visit, once in a while, but not today. I like it here a lot better." He said with a smile. I hugged him and smiled. "Well, it's cute to see you two getting along so well. Mind if I watch with you?" He asked and pointed to the movie.

"I need a serious break."
"Sure."
"Of course!"

I think everyone is a lot happier with my other self around, don't you think?

((I love how this turned out!))