Probably just a "smack you in the back of the head for telling a corny joke" thing, but taken to the extreme despite being so use to his antics.
I think at least part of it is embarrassment over making an accidental pun. (避暑 (escaping summer heat) and 秘書 (secretary) are both pronounced "hisho".)
riviel said:
who is the other in the black-lion's backpack? I see the scientist.
