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1. An unbearable heat by reincarnatedfrog

   Fandoms: Undertale (Video Game)  

   • Explicit
   • No Archive Warnings Apply
   • F/M
   • Complete Work

   12 Aug 2025

   Tags

   • No Archive Warnings Apply
   • Grillby (Undertale)/Reader
   • Grillby (Undertale)
   • Alternate Universe - Underfell (Undertale)
   • Underfell Grillby (Undertale)
   • Reader-Insert
   • Reader is not Frisk or Chara (Undertale)
   • Smutty
   • Explicit Sexual Content
   • Wake-Up Sex
   • Vaginal Fingering
   • No Use of Y/N for Reader-Insert

   Summary

   A quick oneshot in which you find yourself escaping in Grillby's bar under the premise of safety.
   Once you fall asleep due to the comforting warmth and guarding eyes of the fire monster, things seem to quickly heat up...

   This is a rewrite based on a story I wrote like...three years ago? I think I deleted the story, or my entire account, but recently stumbled upon this in my documents sooo.
   Have it! Cause why the hell not?

   Language:

   English

   Words:

   4,597

   Chapters:

   1/1

   Collections:

   2

   Comments:

   8

   Kudos:

   42

   Bookmarks:

   3

   Hits:

   735