Undertale Tickle Stories (Main Series)

A "Humerus" Sleepover (Chapter 5)

Chapter 5 of this long story. In the previous chapter, Frisk, M.K., and Papyrus tickled Sans for an entire hour as revenge for all of the mischievous pranks he pulled during the month. But now it looks like the three of them are going to pay for their actions towards Sans because a mysterious stranger showed up and scared the hell out of them. Whoever this person/monster is, they are NOT HAPPY! WARNING: Things are about to get scary! 

Undertale(c) Toby Fox.

A "HUMERUS" SLEEPOVER

Chapter 5: The Terrifying Stranger

??????: *in an angry tone* JUST WHAT IN GOD'S NAME ARE ALL OF YOU DOING?!!!!

Frisk, M.K., and Papyrus: ... *all three of them stop tickling Sans and are incredibly nervous*

Papyrus: ... *makes the bones disappear*

??????: ...

Frisk, M.K., Papyrus, and Sans: ... *incredibly nervous* (Who is that person?)

??????: I WILL ASK YOU AGAIN!!!! WHAT IN GOD'S NAME ARE ALL OF YOU DOING?!!!!

Frisk, M.K., Papyrus and Sans got incredibly nervous when they heard the mysterious stranger's angry voice and it made Frisk, M.K., and Papyrus stop tickling Sans immediately upon hearing it. The stranger was speaking in a distorted voice and everyone in the room didn't know who it was. Whoever this person or monster is knows Sans very well and is one of the very few that knows he's ticklish.

Sans: (Dude! What the hell?!)

Frisk: ...We're... tickling... Sans... sir... or madam.

M.K.: *clenches Sans's spine with his tail*

M.K. is very scared right now and with every passing second of the stranger's presence, he is only becoming more and more frightened. In an attempt to feel less scared, he clenched Sans's spine with his tail. Whenever M.K. gets really scared, he wraps his tail tightly around something within his reach. And Sans's spine had to suffice since the young boy's tail was already wrapped around it.

Sans: *feels M.K.'s tail clenching his spine* (Ow! Take it easy kid! That kinda hurts!)

Papyrus: (How on earth did they get in here without a key? Nobody except my family and close friends have keys to my home. Unless... No, it can't be!)

??????: DID IT EVER OCCUR TO YOU THAT SANS HATES BEING TICKLED?!!!! WHAT THE HELL IS WRONG WITH ALL OF YOU?!!!!

Sans: (Jeez! I don't hate it that much!)

M.K.: *attempts to run away*

??????: OH NO, DON'T EVEN THINK ABOUT LEAVING YOUNG MAN!!!! YOU JUST SIT YOUR ASS DOWN RIGHT ON THAT COUCH!!!!

M.K.: *downright terrified and clenches back onto San's spine with his tail*

Papyrus: Stop it! You're scaring him! (And me too!) Just who are you?!

Before too long, the stranger emerged from the shadows. The stranger was revealed to be... GASTER!! He told Papyrus that he might stop by after spending time with Asriel, and that's exactly what he did. And to everyone's surprise, Gaster is VERY ANGRY!

Papyrus: Oh my god, IT IS YOU! Why Dad, why?!

Gaster: *in his normal voice* BECAUSE PAPYRUS, ALL OF YOU NEED TO BE PUNISHED FOR MAKING SANS SUFFER LIKE THAT!!!!

Papyrus: But you of all of people should know that...

Gaster: *interrupts Papyrus* I DON'T WANT TO HEAR YOUR EXCUSES!!!! NOW DO ME A FAVOR AND JUST STAY SILENT!!!!