My Life Is the Real Laughing Matter

Dad: Hey son, wanna hear a joke?

Son: Sure thing, dad!

Dad: Your mother and I are getting a divorce. She found out that I was sleeping with the neighbor's dog!

Son: I don't get the joke, dad.

Dad: It's my life, son! My life is the joke.

Explanation

Experiment

The dad tells his son a terrible situation, his divorce due to sleeping with the neighbor's dog. When the son says he doesn't get the joke, the dad explains that his whole life is the joke. It's funny because of the absurdity and sadness. It turns the idea of a joke inside out to the dad's life itself.