An Oath of Mercy || UnderFell Sans x Reader

eight

You switched between staring suspiciously at the back of Sans' head and whispering to Flowey as you all walked home. Sans kept glancing back at you, wondering what you were refusing to tell him.

"We can't trust him," Flowey insisted, glaring at the skeleton.

"How do we know he's even in on it?" you asked, nervously playing with your sweater sleeves as you walked. "He probably doesn't even know about Papyrus' plan." After you'd gotten out of the water, Flowey had broken down what he'd seen from his spot up on the ledge above you. Undyne and Papyrus were walking by as they talked about you, and everything you both heard had shocked even him down to his roots.

"Ok, let's pretend he doesn't know. Why do you think he'll choose us over his brother?" Flowey crossed two leaves over each other like he was trying to cross his arms. The only question on both your minds was if Sans was in on it—well, it wasn't a question to Flowey. You looked over at the skele and he met your gaze before huffing. He didn't like people talking about him so obviously.

"Just tell me what you fuckers are whispering about," he snapped. You looked torn as your gaze snapped from Sans to Flowey, unsure of what to do. So you went with your gut.

"How would you react if I told you-"

"(Y/N)!" Flowey gasped.

"-I wasn't actually a doctor?" Silence met the question as Sans' eyesockets widened and Flowey blinked. Neither of them expected that.

"You saying you fucking lied to me?" Sans' gaze narrowed as he stopped to face you. Your confidence wilted immediately.

"Well it's just hypothetical!" you said quickly, putting your hands up in surrender. He didn't believe you.

"Yeah, she's not a doctor yet," Flowey butted in, and you gasped.

"What are you doing?" you whisper-shouted. He continued, unperturbed.

"She lied to earn your trust. What do you think of that?"

"Flowey!" Sans stood right in front of you, and you faced him with fear oozing out of you, shaking despite the temperature being perfect.

"Why would you lie to me?" His voice was quiet. As if you didn't already feel bad.

"Look, I'm sorry. I'm technically not a doctor yet, you need a piece of paper to achieve that title. But since I'm never getting back to the Surface, and I couldn't be closer to actually getting that stupid paper, I figured it was basically the same thing." You looked down. "But that was wrong of me, so I'm sorry." You winced prematurely, waiting for him to get mad and blow up and hit you, but only silence followed. You peeked one eye open to look at him, and he just looked disappointed.

"Why do you think we would give a shit? It's the same fucking thing as far as I give a fuck. You still know medical shit, right?" You nodded quickly, still mute in shock. "Then it doesn't fucking matter. Doctor, not doctor, whatever." He reached out to touch your face, and you flinched in expectation of it being sharp. But it was soft, comforting, almost loving. "Does a shitty ass piece of paper really determine that much?" You weren't sure if it was a genuine question or just a hypothetical for you to think about. But you found yourself smiling at him, warmth in your (E/C) eyes that wasn't there before.

"Wait, you aren't mad? What's wrong with you?" Flowey gaped at him, and the skeleton just chuckled.

"If you're trying to prove somethin', you failed, flower." His smugness just soured Flowey's face more.

"Were you trying to get him to turn against us?" You all but glared at the flower.

"I was trying to prove he couldn't be trusted, that he'd hurt you if he got the chance!" Flowey protested, earnest even now. You sighed, then pat him on the head. His heart was in the right place like it always was.