When I was a kid, the family was having dinner one night (families did that back then) and one of us kids told a joke that was politically incorrect. My Dad took offense and proceeded to scold us, at one point saying, “That’s about as funny as a rubber crutch!”
Nedless to say, us kids spent the rest of the meal trying, TRYING, TRYING not to burst out laughing, picturing the effects of a rubber crutch.
What can I say. Kids are evil.