Someone asks you a question, you hear them wrong and you say something stupid..

I work in the computer labs at school(Working right now) and this kid is sitting next to my desk. No clue why. He asks me if he can check his email while hes waiting. I thought he was another lab assistant so I said "Uh sure. I work till 12 though..." and he said "Oh, I just wanted to check my email while I wait for him(Nods to his friend)" so I said "Oh, yeah, sure.."
Since when do you have to ask to use public computers in a library? :slap: I felt stupid.