It's rude to speak negatively of something someone likes.
Sal is chatting with some friends about movies when his friend, Jason, mentions that he loved the last Star Wars.
Sal wants to be perceived as a Star Wars expert by his friends.
Sal compares different Star War movies in detail, but stays diplomatic about the weaknesses of the last one.
Sal starts panning the last Star Wars movies, detailing all its flaws and telling James why it's dumb to like it.
James enjoys listening to Sal's opinion without being made to feel bad about what he likes.
James is hurt and feels humiliated by Sal's very negative comments about his favorite movie.