Funny Bones: A Fluffy Undertale Fanfic

Discovery

Bold is me, the writer, talking to y'all reader's, so If you don't wanna read this bit it's fine :). Enjoy the story!

Frisk was walking through the town, that the monster's had worked hard on together to build, on the surface. She had just finished school, and decided to take a stroll through the park before heading home. She noticed a small, familiar figure in the distance, and headed for it. Once realising who it was, Frisk started moving more stealthily, hiding behind trees and bushes incase the figure turned and spotted her.

Frisk was so close now, she could hear them muttering puns under their breath. She hears a particularly bad one, "What happened on Papyrus's and Frisk's date? Can't say, it's too Frisky!" So frisk decides to take action. Tiptoeing closer, she pauses, wondering how to exact revenge on them involving her in one of their puns. Of course! It's risky, Frisk didn't know whether they were ticklish or not, but it was worth a shot! Lifting her arms slowly, quietly, Frisk prepared to- well, not attack. Frisk doesn't attack. Prank, let's say.

A sudden, surprised and out of character squeal arises, followed by a fit of laughter and wriggling. Sans spun around, backing away at a fast pace.
"W-whoa, Kid w-what do you think you're doing?" Sans yelped. Frisk smiled, answering with "Simply tickling that funny bone of yours." and ending it with a wink. "No, no tickling of any funny bones... Please..."
Frisk smiled and reached out to him, wiggling her fingers. "NO!" Sans cowered away, avoiding Frisk's tickles as if his life depended on it. Frisk giggled, letting her arms fall back to her sides and inviting Sans to join her walk to home. Reluctantly, Sans followed at a safe distance.

During their walk, Sans kept glancing at Frisk, as if worried she would try and prank him again. But Frisk kept her hands to herself, talking every now and again, about school, about friends, about a few things she's heard or seen. Small talk. During one particularly long silence, Sans spoke.
"You, uh, ain't gonna tell Papyrus about... Me being... Ticklish, are you?"
Frisk was surprised, she had assumed his brother had already known seeing as they were so close. And why would he not want Papyrus to know, anyway? She settled on an answer the said neither yes or no;
"I'll tell him I pranked you because I'm proud of that." Sans still seemed on edge. They came to a stop by the houses. "Well, see ya!" Sans said, before opening the gate to his and Papyrus's house. He must of expected Frisk to go next door to Toriel's home. But Frisk had expected this outcome, and followed Sans despite him not being too keen on this.