Ever had a joke really fall flat?
Many years ago, before all the current sensitivity about sharp things, I went through a Chinese cooking phase. This meant I had to have a nice sharp cleaver, as per Ken Hom.
Went to the local kitchen shop and bought one.
Then just as I was leaving, I said "She's gone too far this time..." and smiled weakly. The shop assistant looked completely horror struck and took a step backwards.
Ooooops. Obviously murdering the Mrs. is no joking matter!