Why is the theme of infidelity important in "Death of a Salesman?"
When Willie is in Boston on a sales trip, he feels "lonely" and spends some time in the company of one of the buyer's secretaries/assistants. When Biff fails math, he takes a trip to Boston to find his Dad ask him to intercede with his teacher; he believes that the force of his Dad's personality will convince his teacher to change the grade so that he can attend the University of Virginia on a scholarship. When he finds Willie with the woman, he becomes totally disillusioned with Willie and his life. He never goes to summer school to make up the credit, never goes to college, and his life begins the downward spiral that we find him in during the present action of the play.