It is rude to display bad table manners in public
John joins his friends at a restaurant and the waiter brings over the meals.
John wants to have a friendly chat with his friends.
John chews with his mouth closed and avoids making rude comments about the food.
John speaks while chewing his food and complains about the food.
After having a pleasant time with John at the restaurant, John's friends invite him to join them more often.
John's friends no longer invites John to restaurants.