How does he know?

This week I decided that I should stop by Wa11mart. Not a normal thing for me to do. I really dislike going there. However, there's those couple things I want to find in a store that I'm failing on so I really ought to at least check there. Now the only way that I can deal with a trip to the mart is by going in the early am before the ravening hoards of unwashed make their pillgrimage. Normally this isn't a problem, when the husband takes the boy to school I have an extra half hour in the morning. Perfect for dropping by to do a quick shop. Somehow, however, the boy must know. He has desired me as his chauffer every morning. I haven't mentioned this plan, so I just what to know how it is that he knows?