I don't really have any experience with D&D (Except for the watered down version like NWN) so I will need an overview (maybe). As for the time difference based on previous sessions I could only attend during friday and saturday (in your time).
He reacted like as if you were joking then you can say "No I'm not joking I am going to kill you and become a keeper!" and "Yes sorry that was a horrible joke."