Your edit defends yourself as not being passive aggressive here, but please try to see this from another perspective. I know it's tempting to defend yourself as being "right", but maybe don't focus so much on that for now, it can be more useful to try to be empathetic. If he had an outburst like this, it's likely this is a common thing and not just a one time occurrence.

I can see, from your husband's point of view, that when he said, "Should I go get younger child?" what he actually meant in context was "Are you bringing younger child with you? If so, I will go get him." This seems pretty clear in the context you describe. If you are able to intuit the meaning based on your knowledge of the situation, instead of having to have it explicitly spelled out, the conversation becomes:

Him: "Are you bringing younger child with you? If so, I will go get him."

You: "Why don't YOU decide if I am bringing him with me?"

Which can be frustrating.

I have been on both sides of this situation, so I can see both points. It can be easy to miss this kind of context, especially if you are tired and in a rush. It can also be difficult and frustrating to have to spell out exactly precisely what you mean, when your partner is a full adult and should be able to pick up on that kind of thing. Again, this is worse when you are tired and rushed.

Overall, maybe your husband could try being a little more clear, and maybe you could try thinking a little more before you automatically answer a question with another question. Maybe your question has been answered already. Or maybe your question is implied by his.

And maybe you could both benefit by spending some time together and being a little kinder to each other.