How to reply when I go to the supermarket to buy lunch boxes?

You can reply with messages such as "pay attention to safety on the road".

You can ask him if he is tired or if he has eaten? How are you today? Are you in a good mood? Aren't you happy? These are all fine. If you still want to continue talking about that topic, you can ask him what he bought for it. Well, why didn't you tell me before? I can help you buy some.

You can also change the topic or what happened today, or you can say when you can meet or make an appointment. In fact, sometimes chat with him, don’t be too restrained, you can find what you like. topic.