As children, and then adolescent people, my siblings and I were made to understand that we could ask our mother anything. No question was taboo and she would answer as straightforward and honestly as she was able. Any time, anywhere, any subject. The lines of communication, she wanted us to know, were always to remain open in our family.
There was one question, though, that was never to be spoken. After a long day of ... working with computers? (I'm still not sure what she does) ... when she returned home, she did not want to hear "What's for dinner?" Now, we were always well-fed and never, for a single night, went hungry, but she wasn't running a boarding house, she was a ... computer person? What was for dinner was whatever she was making for dinner and it will be ready when it's ready. So don't ask.
We haven't had to tell The Quartet yet that they can ask us anything. They ask us anything and everything already. Question after question after question. It's like living with The Riddler times four. They ask who's coming over, they ask what's on TV, they ask where their mother is, they ask what we're going to do next. And they ask, every night, "What's for dinner?" I've told them I didn't want to hear that question because it's rude and because it still scares me a little bit.
The really odd part is that these kids don't eat whatever we're having for dinner. I mean, there's what we (Kristy and I) are having for dinner and there's what they're (they're) having for dinner. And those are never the same thing. Oh, sure, S will accept what the adults are having to push around on her plate and whine about and eat a bit of just so she can get to "What's for dessert?" But you're not going to catch JP having spaghetti or C eating a burrito. It's just not what's for (their) dinner.
So don't even ask, because it's rude. And, coming from you four, it's just dumb.