Undertale Tickle Stories (Main Series)

A "Humerus" Sleepover (Chapter 6)

Chapter 6 and the conclusion to this story. In the previous chapter, the terrifying stranger was revealed to be Gaster and he acted like a really nasty jerk to everyone in the room. But at the end of the chapter, it was revealed that the reason for acting the way he did was all just a prank to scare Sans. And he succeeded. ;) All Gaster has to do now is clear the air with Frisk, M.K., and Papyrus. :D After he's finished ticking Sans that is. ;P

Undertale(c) Toby Fox.

A "HUMERUS" SLEEPOVER

Chapter 6: M.K. Makes a New Friend

Sans: AHAHAHAHAAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAA!!!!!!!

Frisk: (Oh... my... god!! I can't believe it was all just a prank!! Way to go Gaster!!)

Frisk and M.K. were so relieved that they weren't actually in trouble. The two of them of have never seen Gaster angry before and Frisk's frown turned upside down really fast the moment she found out it was all just an act. And what a VERY convincing performance too! Gaster was WAY MORE intimidating than Undyne! Papyrus was so surprised that he fainted! Unknown to everyone, Gaster showed up much earlier (around the time Papyrus began helping the children tickle Sans) and hid from everyone before initiating his terrifying prank. He purposely let Sans get tickle tortured by Frisk, M.K., and Papyrus before stepping in. But he's not going to tell Sans that!

Sans: WHAHAHAHAHAHAHAHAHAHAHAAHAT THE HEHEHEHEHEHEHELL?!!!!!!! AHAHAHAHAHAAHAHAHAHAHAHAHHAHAHAHAAHAHAHAHAHAAHAHAHAHA!!!!!!!

Sans is completely shocked right now. He couldn't believe that everything his father did was all just a prank. Gaster lifted him up in the air just so he could tickle him for thirty seconds. Gaster figured it should be short since scaring the hell out of him was his primary goal and since Sans already got tickle tortured for an entire hour. And even though Gaster gave Sans a taste of his own medicine, he definitely knew that he went too far. He felt terribly guilty for including Frisk, M.K., and Papyrus in the prank, but he thought that Sans would've been able to tell if they were in on it and he wanted to make it as convincing as possible. He succeeded. The reason he yelled at Frisk, M.K., and Papyrus and acted like a heartless jerk to them was to see if Sans would stand up for them and prove how much he cares about them, to which he did. Gaster knew he could make Sans mad enough to attack him, giving him all the more reason to "punish" him. The crazy thing is, Gaster isn't even mad at Sans for attacking him. He probably would've done the same thing if he was in Sans's position. Everything fell into place very nicely, even better than what Gaster anticipated actually. Except for making M.K. cry, that is.  

Sans: AHAHAHAHAHAHAHAHAHAHAHAHHAAHAHAHAHAHAHHAAHAHAHAHA!!!!!!!

Gaster: You just got pranked Sans! Not so fun being on the receiving end of them is it? Papyrus told you that someone would get you back! *stops tickling Sans* You just didn't think it was going to be me, did you?

Gaster then made the hands disappear and gently placed Sans back on the couch.

Sans: No, I didn't! I gotta say, you really scared the living hell out of me! Last time I got that scared was six months ago when I thought Frisk died!

Frisk: *smiling* (Awwww! It warms my heart to hear how much you care about me Sans!)

Gaster: Well you can rest easy now Sans. It's all over. I deeply apologize for everything I've done. Kids, I'm sorry I included you in the prank. I truly didn't want to scare you like that. It's just that Sans has the tendency of knowing if someone's in on a prank.

Frisk: I understand Dr. Gaster. You just wanted to make it as convincing as possible.

Gaster: I knew you would Frisk. Now if the two of you don't mind, there's a frightened child sitting next to you that I'd like to speak with. But perhaps I should help Papyrus regain consciousness first.