Jonatello oneshots I found on ao3

Don't stop talking

Credits to aliennopossumm
Summary:
Donnie get insecure over his unprompted infodumps, but Casey reassures him that he enjoys listening.

"And it's always been an interesting topic to me! I mean- just the amount of people who will argue that the moon landing was a fully staged event is fascinatingly stupid, in my opinion. There's plenty of evidence supporting that it had happened. Humans undoubtedly had the technological ability to do so, even in 1969, so I..." Donnie trailed their words off before clearing their throat. They briefly smacked their lips as they looked down to the tools spread across their desk, "sorry, that was a tangent completely unrelated to what we are doing. I'll stop talking now."

"Why? I liked hearing you talk," Casey assured quietly, tiredness clear in his voice. He was awkwardly sitting in a desk chair of his own, gangly legs hanging off the right armrest, his back pressed up against the left with his hands resting on his stomach. "Don't stop talking."
"Aren't I boring you?" Donnie swiveled his chair around so they would face their boyfriend, "it's late, and you're tired, and I assume you don't exactly... understand what I'm talking about when I'm explaining how rockets are made, no offense."

"None taken, I do not," the taller boy chuckled lightly, moving one hand to grab onto the side of Donnie's desk before spinning himself around. "But I do like hearing you talk."
"You just said you don't understand what I'm talking about."
"For someone so smart, you're so incredibly dense," Casey teased, pushing himself in circles once again to keep himself entertained, "I like hearing you talk because sometimes I learn shit! I'm into mechanics too, y'know that - and besides, when it's something I'm not understanding, I like hearing you talk. Your eyes go all wide, and you get this big toothy grin, and it's... kinda really cute. I like when you go all dorky."

Donnie couldn't help the sligh blush that tinted at their cheeks. They turned their gaze away from Casey and looked back to the current project that sat on the desk, something that had not been tinkered with for the past couple minutes due to their infodumping. Being unable to respond to affection, they just shrugged at the boy. "You're a dork too..."
"That's up for debate," Casey added with a yawn, the chair's spinning coming to a stop.