You shoul not steal from people who trust you.
Donald sees a computer game he really wants at his best friend John's house.
Donald wants to take the game home to play it.
Donald asks John if he can borrow the game for a few weeks.
Donald puts the game in his backpack without telling John.
John lends Donald the game and feels happy to help a friend.
John later finds out the game is gone and loses trust in Donald.