Taking it all in

Last night Sam confused my exasperated tone with being upset and said to me, "Mom. Not be cross."
He's only heard the word, cross, on Thomas the Tank Engine videos as we certainly don't use that in our everyday language. I think it's pretty cool that the very first time he used the word, cross, he was right on as far as the context goes -even if he did think I was mad when I really wasn't. Goes to show that they are watching everything we say and do!