A/N: I didn't get this joke when it was first explained to me. Took me a while. .
Wash stared across Valhalla at the red flag flapping in the wind atop the other base. He was slightly out of it, lost in his thoughts and day dreaming. He still hadn't adjusted to life with the Reds and Blues, though he was coping. Hell, he was lucky to even be alive and he knew it.
"Agent Washington!" Caboose called, running up behind him. Wash turned around to see the blonde haired private grinning excitedly.
"What is it Caboose?" the former Freelancer asked as Caboose rolled up his sleeve.
"Tucker and I have started a secret club!" he exclaimed.
…why do I have a bad feeling about this? Wash inwardly groaned, taking a step closer to read what was written on Caboose's arm.
There, on his arm in black permanent marker was a scribbled "PEN15". Wash stared at for a second, trying to figure out if he should explain or not. Finally, he settled for just running his hand down his face.
"Caboose, you should just try and get that off," he said into his palm.
Caboose didn't understand what Wash was meaning, so he assumed it was Wash that didn't 'get' it. "No you see, we are called the Pen club! Tucker said he was the 14th member, so I got to be number 15! Though…I do not know who any of the other 13 members are…"
"Caboose it's not a…" Wash started. "It doesn't mean what you think."
Caboose now looked even more confused by his words. He tilted his head slightly to the left, his eyebrows creasing in the middle of his forehead. "You mean we are not in a secret club?"
A short sigh came from the former Freelancer. "No, no you're not."
"Then Stupid Tucker is a liar?"
"Yes, he is."
"…then what does this mean?"
Sister came walking out of the base just then, having been finally reassigned to the new Blue base a few days previously. She still had no idea that the blue and yellow clad soldier leading them was the cop that had been in Blood Gulch months previously.
She looked down at Caboose's arm and laughed. "Dude, why'd you write penis on your arm in big letters?"
"What? It does not say that! It says Pen 15!"
"No, that's penis. Trust me, I know a penis when I see one," she said.
"Mm, that's no surprise," Wash muttered.
Tucker appeared in the center of their little half circle, he was sucking on an ice pop. "Hey Caboose, you figure out the secret code in our club yet?"
Caboose glared at Tucker before pulling his sleeve down. "You are a very mean person Tucker!" he snapped before turning on his heel and stomping back towards the base. "I am leaving!"
"God, I thought he'd never figure it out!" Tucker exclaimed, busting out into laughter. "I've been waiting to use that joke forever!"
"You're a fucking idiot," Wash said, crossing his arms and narrowing his eyes at Tucker. Tucker suddenly noted that Wash bore a strong resemblance to Church in that moment; at least in personality. "Caboose is like a big kid, you shouldn't be so mean to him."
"What? Man, that's bullshit," Tucker groused. "Come on, I'm using a grade school prank against him. Like you never got that pulled on you when you were a kid?"
"I was home schooled."
"Yeah see that's my- woah, wait…really?"
"Yes?"
Tucker scratched his head. "Wow, that….explains a lot, actually. I hear home school kids are really socially inept."
"Well, you heard wrong!" Wash snapped. "I don't have any problems socializing."
"…yeah, right, sure. I believe that," Tucker said, nodding. "Just like you know how Big Foot exists."
"And Pumas!" Sister chimed in.
The two males turned their attention to her. "Pumas actually do exist, though," Tucker said.
"What? No way! I saw a thing on TV once! Or maybe that was Saber-tooth cats…"
Wash groaned again, growing tired of the idiocy. "Just stop doing that stuff to him, okay Tucker? It's not that hard to act like a decent human being."
"Yeah, I know," Tucker retorted. "You should try it sometime." He smirked at Washington before turning and heading back into the base. Wash's eyes were shaped into a pointed glare after him. Sister let out a low whistle.
"Man, what a cockbite he is," she said.
"Yeah…" Wash muttered.
"Wanna sneak into his room tonight and draw a dick on his face?" she suggested happily. "It's only fair!"
"Sinking to his level wont solve anything," he said.
Sister shrugged. "Fine, suit yourself," she said, walking towards the direction of Red Base to go bother her brother, leaving Wash standing alone outside of Blue Base.
Despite what Wash had told Sister, no one commented when Tucker woke up the next morning with half his head shaved and a giant dong drawn in on his exposed scalp and forehead.