This one's a short, all-dialogue drabble. Had this in mind, and…why not? Just a tip: Sherlock's the one with more words :P
"TAG, YOU'RE IT!"
"Why you no running?"
"It's 'why you're not running?' And I'm not running, because I'm reading."
"But we're playing tag!"
"You are playing tag. I have no part in it."
"Oh, well. TAG!"
"Why'd you do that again?"
"'Cause you said you no part-"
"You've no part"
"-in it, so now i make you part in it!"
":D"
"Leave me alone."
"Aww. Play with me, please?"
"No. I'm busy."
"Reading's booorring. Playing tag's fun! Come on!"
"How is being chased by someone who is potentially bigger and faster than yourself, who may or may not have a mean and scary face, and follow you around the court until you tire, which then he'll be able to tag you, and ultimately you becoming this so-called tagger, fun?"
"…"
"…it's great exercise."
"Once again, leave me alone."
"Whatcha reading?"
"Something your little brain can't comprehend."
"What's 'comprehend'?"
"Understand."
"Yes, i can! See-"
"Hey!"
"-this one! 'I' means me, right? Correct?"
"Understand the concepts, not words."
"…oh. Still, reading's boring."
"You're gonna have to read a lot when you grow older, so might as well start now."
"…oh. Umm, when i go home, I'll read my storybooks. Th-that's okay, right? Reading storybooks, instead of thick books - like yours?"
"Yes, yes, that's fine."
"…"
"I'm going. Mummy's calling."
"Okay."
"Oh, and…"
"Hmm?"
"…"
"…tag."
"…"
"…eh? Wha?…THAT'S CHEATING!"