Flip My Switch (Mettaton x Reader)
When monsters return to the surface with your missing sibling, Frisk, you're more than happy to make friends with them. One monster in particular seems to show you special attention, but before long humanity is eating out of the palms of his hands. It would seem he's forgotten you, but maybe he hasn't.
Mettaton x Reader
(The reader is gender neutral in this story, although I doubt that I will bring up the reader's gender often)
IMPORTANT: At one point in the story, you will have to make a decision. If you choose one, the tone of the entire story will change. He will stop at nothing t o m a k e y o u h i s .