It is rude to refer to people as homeless.
Jon's friend Ken just told him that he has to live on his brother's couch.
Jon wants to say something to his Ken.
Jon tells Ken that he's lucky to have his brother in his life.
Jon tells Ken that he should just say that he's homeless.
Ken agrees with Jon and feels more appreciative of his brother.
Ken feels insulted and thinks that Jon is a real jerk.