Refusing to speak to someone is rude.
Stacy is on a long flight when her seat mate tries to start a conversation.
Stacy wants to relax and read a book.
Stacy tells her seatmate that she would like to quietly read.
Stacy opens a book and starts reading without acknowledging her seatmate.
Stacy's seat mate thanks her for her honesty and leaves her alone for the rest of the flight.
Stacy's seat mate calls her rude and feels offended.