It's wrong to steal things from other people.
Nathan is visiting a friend, and his friend shows him a really cool video game that he got recently.
Nathan wants to get a copy of the game for himself.
Nathan goes to the store on the way home and picks up a copy of the game.
Nathan tucks the video game into his jacket right before he leaves his friend's house and takes it home without asking.
Nathan's friend is excited that he got the game and wants to play it with him online.
Nathan's friend finds out and gets angry at him for taking the game.