You are a babysitter

You are a babysitter, who was hired by Frisk and Sans to take care of their youngest son Sink, because Astell was not available at the time

When you arrive at the house, you see the tender Sink sitting, with a fixed gaze, eyes that are too beautiful, like a rainbow color, he has a small smile when he sees you, waiting for your command (Although, he hardly obeyed anything)