Mafiatale Sans x female reader (Possession)

A Change

I couldn't sleep that night knowing that I just confessed to Sans and the fact that we both want to be together despite how dangerous our lives might be. I get out of bed and decided that maybe a nice bath would help me sleep and get my mind off of Sans.

     The water felt nice on my unclothed body as I lowered myself in and could feel the sleepiness already taking over me. I let my thoughts drift about my mind as I closed my eyes, but the peace only lasted for a second as I felt an unexpected splash on my face. I open my eyes in confusion and saw Bella happily splashing about.

     "Bella? How did you get here, I thought Gaster was watching you in his lab."

     Bella ignored me and fluttered over to a large vent on the ceiling. The highly detailed metal pattern that covered the vent looked too small for anything to slip through any of the holes, but Bella proves me wrong by squeezing through the spaces and instantly coming out the same way she went in.

     "Does Gaster know that you've escaped through the vents?" I ask.

     Bella was fluttering uncomfortably on the other side of the tub and looked away as if she was trying to avoid my gaze like any child would do if they knew they've done something wrong.

     I sigh knowing that Gaster will have a panic attack the moment he wakes up and can't find Bella and figured that returning her is the least I can do. I leave the tub's warm embrace and dried off enough to change. I turn around to immediately scold Bella for being irresponsible but watching her splashing and dancing in an even bigger water source than a sink was enough to remind me to tell her how she can't run off without asking permission.

     I finish changing and carefully scoop up Bella from behind and quickly dried her off with a hand towel. I could tell she wasn't happy with me interrupting her from such a short bath by her whispering voice, sounding louder along with her exasperated fluttering around my head.

     "Now Bella, you know you're not suppose to leave Gaster's sight. What if you wandered out of the mansion and some bad monster finds you and takes you away?"

     She stops fluttering around my head and sits on my shoulder in a pouting manor. I leave her be and unplugged the tub and make my way to Gaster's door. I didn't have a key to let myself in like Sans and Papyrus but not long after standing in front of Gaster's room, the door had unlocked itself and slowly creaked open. To my surprise, Gaster wasn't far from the door as his hand glowed a dark purple as well as the door knob. I step inside and the door closes behind me and the sound of a lock took place. I look at Gaster in amazement as he returned a smug smile.

     "Did you do that on your own?" I ask him.

     Gaster nods at me and gives Bella a glare who refuses to leave my shoulder.

     "Then what's the point of locking you in here if you can easily unlock the door by yourself?"

     Gaster opens his mouth to speak but he stopped himself before he could continue. He had a look of frustration as he waves off my question and gestures me to follow him to the lab. 

     Bella stayed on my shoulder but slowly started to hide farther behind my head as the lab came into view. Gaster turned to face me but he contorted with confusion as he stared at my shoulder where Bella was no longer in sight. Gaster points to my vacant shoulder and looks at me for an explanation. I point to the back of my head and turn around, exposing Bella to Gaster. He tries to carefully pry Bella off the back of my head but she managed to cling on even tighter, making it difficult for Gaster to pull Bella off without taking a handful of my hair with him.