Sudden Changes (Undertale Sans x reader)

You were a normal human living on the surface until one day, monsters appear from the underground due to the barrier being broken by a small human child called Frisk.

The monster and humans tension grew as society could not accept them after knowing what they had done to get to the surface.

You don't think much of it, until encountering some interesting monsters, one of the monsters in particular catching your interest.

Your bestfriend, who has been with you most of your life does not seem to accept them at first.

(THERE IS CURSING)