In those situations, we get revenge for DS6's toddler years by pestering him with whys and hows.

And in the same light, I suppose we cast him into the role of junior psychoanalyst. Why do you think he feels that way? How would that make him feel? He also likes to do freeform play where we make up characters and situations together. If something has happened that seems to want exploring, but he is reticent, I can explore it more obliquely.