Didn't really think about it, dd had friend round, both seven, and friend asked for drink (bit of a tone in the way she asked). As a reflex really I said, "say please" and she informed me that she didn't have to say please. I, bit less reflex this time, said that we do in our house. Mother rang me the next day to say that what I'd said was unacceptable. I promise faithfully that both comments to her dd were made in a pleasant tone! Aibu?