can't take the heat? get out of the pillow fort

!!I DIDNT WRITE THE FIRST CHAPTER !! this is a story that was published in 2017 on a03. same title and everything original author is : Petalrxse. since over 7 years have past I think it's safe for me to republish with a second chapter and possibly more.
it's a Sans x Reader scenario contains : Heat, and smut as well as feral (non animal) kink