No, thank you

So we are trying to teach the boys about politeness. We try to explain that “Mommy, bring my teddy’ and ‘Mommy, give me a cookie’ are not the way to ask for things.
And of course when they get a cookie, we explain to them that saying ‘thank you’ would be nice. So far our efforts have had limited succes. But toddlers would not be toddlers if they would not also use your teachings against you.
So when I say to them: Do you need to do a pipi on the potty?, they cleverly reply: No thank you.
Cheeky little things!