You should be very polite when visiting other people's home.
Mary is visiting her in-laws' house for dinner one night when she notices a tasty looking pie cooling in the window.
Mary wants to try the pie.
Mary inquires about the pie and says that it looks very tasty.
Without asking Mary removes the pie from the window and scarfs down most of it using her hands.
Mary and her in-laws each have a slice of pie after dinner and enjoy its delicious flavor.
Mary's in-laws' are offended by her rudeness and lack of manners and form a negative impression of her.