A/N: Yo! Here is a short Undertale one-shot based off the prompt: "I never meant to come between you and him."
Please leave feedback, but keep in mind that it's supposed to be short! Enjoy!
Sans stood outside of his cabin house located on the main street of the popular town of the Underground called "Snowdin" where he couldn't help but give is famous cheeky smirk to the even more popular Underground sensation known as "Mettaton", a product that Alphys, the Royal Scientist, had created to show off her skills of what she was capable of plus some nice cash that would roll in if Mettaton became a household name to the monsters trapped on the wrong side of the barrier. Mettaton, however, felt the need to break out of what he considered "the norm" and become a human killing robot, as if humans flooded the Underground. No, the only human that was currently living down beneath the ground was one of his closest companions and roommate, Frisk, and Sans saw it as one of his jobs to take care of them. This job, however, he'd actually put effort into. She was a part of every unfortunate timeline that they shared, so why not make the best of it?
Staring back at the overly dramatic piece of metal in front of him, Sans gave a small chuckle. He blocked the door to his home with his own body, being a physical barrier between his home and this . . . man. Mettaton crossing his black sleeved cold arms and watched, shaking his head with his black hair following suit. He asked Sans, as if it was obvious why he was here, "How about you step aside and let me see your brother, hm?"
The small skeleton grinned, knowing his night just got interesting. With each reset brought new actions for Mettaton to carry out. Wasn't it odd that despite the several hundreds of resets in the timeline that Mettaton never followed out the same steps or moves? He always had something different. For a robot, he really was one of a kind. Sans shook his head as the grinned remained plastered on his hollow skull. He answered with his normal relaxed tone, "No can do, gorgeous. I see what they say about you on the TV and in the magazines. Between your 'scandals' and other misadventures, no way am I letting you near my brother. He's pure because I've kept him sheltered, sugar."
Mettaton giggled, covering his mouth as he stood out in the snow. He asked, his voice muffled through his robotic hand, "Sheltered? He's alive, but he ain't living, darling. Take it from me. I know all about living. He needs a life."
Sans rolled his white pupils. Ironic that the robot was giving life advice. With a shake of his head, Sans leaned against the wooden door frame that never sat right due to Pap's unexperienced in building. He tilted his head, watching the model not budge as the silence rang out between them. With a yawn, the smaller continued to watch the other, assuming that he'd get bored and storm off back to his expensive lounge. Besides, Sans knew he could weigh out his will longer than this scrap metal. He had more determination.
Mettaton, not being one to give up, stepped a little closer and persisted. "Come on, darling. Let me see him. You know he has a crush on me. Why can't you let him be happy?"
The skeleton thought about it for a moment, unsure of really what to say. In all honesty, the other was right. It was clear that Papyrus loved the television star, even going as far as sharing his ideas of marrying the robot some day in their own little town. Standing outside blocking his brother from his crush made him really wonder why he was doing this. Never in any other previous timelines had he allowed the two to interact past going to see one of Mettaton's live concerts in the front seats, close enough to smell the oil from a few feet away. Sans rubbed his hand for a moment, coming up short on what to say.
The robot sighed, the static tone in his voice asking with true honesty, "I was just coming by to give him this. He was talking about how much he loved spaghetti on the phone with me, so I figured maybe you should have him try some chocolate. Yes, I know, it's rare because you can really only find it on the Surface. Some people claim that the humans eat it often."
With hesitant steps and slow movements, Mettaton walked to the dead enemy and handed him a small heart shaped box from his leather pocket. The box was MTT's signature pink with a lace red bow around it, only big enough to hold around three chocolates since they were such a luxury among the monsters. Sans sighed, reaching out and taking the box. He commented once the heart was in his hands, stepping back to give them distance, "You're really a pain, but at least Pap doesn't think so."
The second he finished his sentence, the door behind him was opened abruptly. The taller brother appeared, instantly calling out in a sing song voice, "Guess who made spaghetti! I-"
He stopped talking when he saw a wide eyed Sans holding a heart shaped box. Mettaton grinned at seeing Papyrus, but audibly gasped when Pap scanned the two while saying, eyes squinted, "Oh. I see. Sans, you didn't tell me you also loved Mettaton!"
Not sure whether to laugh or try to make an excuse, Sans tried his hand at saying, "No, bro, I was just-"
Papyrus shook his head, crossing his arms with a smile. See, anybody else would have been upset that their crush supposedly was in love with another, but Pap wasn't any normal being. He beamed, clapping his gloved hands together, "Wowie, you two are such a great couple! I knew you two had chemistry! I-I should have knocked before I opened the door even though I was going outside to see you, brother!
The happy skeleton sighed out, smiling wide at the scene he just found, "I should have knocked. Yep. I never meant to come between you and him in such an intimate moment, Sans. Don't mind me. I'll just be . . . cooking."
Papyrus ran back in as Mettaton held up a finger to speak, slamming the door in their faces. Papyrus instantly ran to the window that faced the outside and stared from behind the curtain, unaware they couldn't see him. Sans awkwardly gave out a laugh, stepping backwards and opening the door without looking back at it. He and the robot shared a very odd, uncomfortable stare before Sans stepped inside his house and closed the door, wordlessly.