Jay laughed, the sound filling the cortex. "Just kidding. Of course we have bananas on Earth-2."

"Oh," Caitlin said.

"Just a joke."

Caitlin didn't laugh. Her smile was a little tight. "It's a good thing you're cute."

Cisco slid down in his chair behind the calc board, muttering "haaaaaachi mama," under his breath.

He waited until she'd gone into her lab to check some test results. Then he straightened up and said, "Jay. Man." He waved at the other man through one of the patches in the clear plastic where he hadn't scrawled a mess of numbers and Greek symbols. "Hey, Jay, c'mere a moment, would you?"

The other man strolled over. "Yeah? You need help with something?"

"No, I'm cool. Actually, I wanted to drop a little help your way." He kicked an extra chair out so Jay would sit, because he was so damn tall it was hard to have a conversation. "It's about time to retire that gag, man."

Jay didn't sit. "Which one is that?"

"You know. What you just did? The one where you're like, 'what do you mean? We don't have the color purple on Earth-2, can you explain it to me?' And then you're like 'aha, just messin witcha!'" He peered upward. "You know? That one?"

Jay shrugged. "It's just a joke. Caitlin has a good sense of humor."

"She does, yeah." His neck was starting to hurt. "But she's getting pretty tired of that one, I can tell."

"How?"

Cisco blinked at him. "Because I'm one of her best friends, and I know her tells?" Like. Caitlin was about one-point-five more of those jokes away from giving Jay a goddamn piece of her mind. How did Jay not spot that?

But Jay had only been around a little while, and he'd never seen Caitlin really give it to anybody yet. So maybe he couldn't spot the signs. Certainly it had taken Cisco himself at least two nuclear Caitlins before he had figured out where the line was, and that was when Ronnie was around to widen his eyes and make throat slashing motions behind her back.

"Really?" Jay said. "You."

"Uh, yeah." Okay. His neck was not going to take this much longer. He stood up, too. He was still like a foot shorter than Jay, but the angle was a little better at least.

"Sorry, I guess I just missed that about you two. I mean, she didn't even talk to you for six whole months, that's not what I would call best friends."

Whoa. Wow. Okay. "Uh, th-that's not what we were talking about, and besides, you probably don't realize that's actually kind of a defense mechanism for her. Shutting down. Which actually I know, because y'know. Really good friends, been through a lot together. Um. But that wasn't my point."

Jay tilted his head. "What was?"

"The joke," Cisco said. "Let it go already."

"You know, Caitlin wouldn't play along if she didn't think it was funny too."

But she's not playing along, Cisco thought. How do you not get that? He mustered up as much diplomacy as possible. "You're right, she's got a decent sense of humor. But she's also got finite patience, and take it from me, that joke's wearing on it."

"Why do you care?"

"Because she likes you - " Although Cisco couldn't exactly come up with a good reason for that at the moment, besides hawwwwwt. " - and I'm trying to clue you in before you step in it. Just being a pal."

Jay's eyes flicked over him, up and down, and then he shrugged again. "Well, I guess I can dial that back a little. If you really think she'll get upset over a meaningless little joke."

Cisco bit his tongue. "All I'm sayin'," he said brightly. "I mean, you're a pretty fun guy. You can come up with other stuff to make her laugh." Not that she'd ever really laughed at that. Not a real laugh. But whatever. As long as Jay cut it out and Caitlin didn't have to have a fight with somebody she really liked and she kept smiling the way she was lately.

"Oh, I'm sure I can," Jay said, and Cisco had to bite his tongue again for some reason.

He leaned over and peered at Cisco's calculations. "Hmmm, he said.

"What?"

"Just - you're using that equation? Interesting. Not what I would've picked."

Cisco looked at the board and blinked a few times, frowning as Jay walked away.

FINIS