It's rude to use humor at the expense of others.
Chris and his friends are sitting at the food court in the mall talking and people watching.
Chris wants to entertain his friends.
Chris relates a tale of camping trip he took with his family that was full of adventure and good times.
Chris makes a fat joke about the size of a portly man walking by the food court with a tray of food.
Chris elicits many laughs and commendations from his friends for his wonderful story.
Chris is called out for his uncouth joke by all his friends.