fanfiction-spiderman & ironman:Repeat After Me by battybatzgirl

Tony’s face hardens as he says, “What kid.”
“I don’t know, some twelve year old—”
Below him, the kid coughs out, “Fifteen.”
“—Fifteen year old—”
Tony scrubs a hand across his face. “Don’t tell me he’s wearing a dorky shirt with a chemistry pun on it.”
Rhodey frowns. That was oddly specific. Glancing down, he looks at what little he can see of the kid’s shirt—which isn't much since there’s so much blood now, but what could be once called a cartoon joke is printed on it. “Um, yeah?”
“Son of a bitch.”

Otherwise known as how Rhodey finds out about how old Peter is, and how badly he needs to beat Tony with a stick.