It's in Lucky Leon smile Clark listens in to a conversation between Jimmy and Perry. Lois assumes he's lip reading and asks him what else he can do that she doesn't know about, and he tells her he can order dinner in 347 languages.
It's right before the whole 'charcoal suit/burgundy dress' bit.

"It means never having to play it cool about how much you like something. It's basically a license to proudly emote on a somewhat childish level rather than behave like a supposed adult. Being a geek is extremely liberating."- Simon Pegg