Willy and Biff have a troubled relationship. Willy's grandiosity and refusal to live in reality have almost ruined Biff's life. During the course of the play, Biff comes to terms with this reality as he tries to change his life and steer a psychologically more healthy course than his father's.

By the time Biff is a teenager, it must have been apparent to Willy, whether he wanted to admit it or not, that his dreams of being a wealthy salesman sitting in a hotel room in his velvet slippers as the telephone orders came flooding in is not going to be his reality. In truth, Willy is a mediocre salesman struggling to survive economically. Therefore, he pins his hopes and dreams on Biff.

He decides that Biff is better than other teens and will have the success he never had. Because Willy defines success as using your personality to dominate others and fast talk your way to wealth without having to do the hard work of gaining expertise, Willy pushes this way of living on his son. He doesn't encourage him to work hard in school and instead praises shallow "values," like popularity and putting things over on people, such as through petty theft. He never encourages his son to go to college. He also badly disillusions Biff by having an affair that Biff becomes aware of in high school. Biff is not impressed by, but instead is angered and shattered at his father's deceptions and betrayals.

Biff tries to get across to his father during the play that he has himself wasted many years being misled by his father's delusions but now has every intention of accepting being an ordinary person and living in reality. He has seen the destructive quality of his father's desire to be bigger and better than everyone else, turning life into an endless, pointless competition.

Willy, on some level realizing he has been a miserable failure, tries to make things right with Biff the only way he knows how, which is to commit suicide so that Biff can inherit his insurance money and have a fresh start.

The relationship between Willy Loman and his son Biff isn't a good one, and that's mainly because each one has, to some extent, disappointed the other's expectations. Willy had always wanted Biff to be a high-achiever, to become “a well-liked man,” which for him is just about the most important thing in life.

Initially, it seemed that Biff was going to do his old man proud and become a star football player. But after he flunked his math test and missed out on a football scholarship, his dream lay in ruins.

But it takes two to tango, as they say, and Willy disappointed Biff. When Biff found out that Willy was having an affair with a secretary, such was his trauma that he went completely off the rails. In fact, he was so hard-hit by his father's infidelity that it affected his school work. It's no exaggeration to say that Biff's flunking of his math test and missing out on a football scholarship was the direct result of his father's transgressions.

As a result, father and son have a very bad relationship. Willy can't help but remain disappointed in Biff, and Biff can't respect Willy, not just because of his philandering, but also because he's become something of a dinosaur in the world of sales even though he still acts like he's a hot-shot.

The relationship between Biff and Willy can be described as turbulent, dysfunctional and, actually, dissociative.

It is turbulent because the history of angst, secrecy, and disappointments between Willy and Biff prompts instant arguing and fighting between the two men, at any given time.

The angst on Biff's part comes from the disappointing discovery of his father's affair with "The Woman." This discovery occurs during a time in Biff's life when his high school successes have just come crashing down, and he needs the support of the very man who builds him up and puts him on a pedestal.

Knowing that this very man, his father, is capable of lying and deceiving puts Biff in a diatribe: IS he the "wonder child" that his father, the liar, has made him out to believe he is, or is Biff Loman yet another one of Willy's "lies"?

On the other hand, the fact that Willy knows how Biff feels about him after the discovery is a huge bad blow to his ego: he no longer has his "wonder child" to boast about, and he can no longer continue his project of making Biff everything that Willy wished he could have been. Hence, the men's communication falls apart and seems to only lend itself for conflict. 

The relationship between Biff and Willy is dysfunctional because it lacks the defined boundaries and limitations of affection and mutual respect that should exist between a parent and a child. In a healthy parent/son relationship the father nurtures the son and lets him develop according to the child's own possibilities. Willy does this, but not altruistically: he builds Biff as a more handsome, more talented, and more successful version of Willy in order to vicariously re-live his lost years.

As a result of the lack of proper boundaries between father and son, Biff sees his father as his rival and enemy during trying times. Rather than trying to seek a reconciliation that would enable them to move forward, they basically go head-on against each other like if they were not even related. This is the epitome of a dysfunctional parent/child dynamic. 

Finally, the relationship is dissociative because both men have lived, either in denial or in complete dissociation, of the reality of their lives. Their lack of focus on themselves as individuals, makes it impossible for them to view themselves as part of a healthy relationship. Willy sees himself as a hot shot salesman, sees Biff as a hot shot football player, and sees his American Dream fulfilled. As a result, Biff starts to be sucked into Willy's dream and ends up believing the same things...until reality hits Biff and he realizes that his life had been a lie, all along. Hence, Biff moves out West trying to find himself. However, as he himself says, "something" always brings him back. 

Therefore, dissociation, turbulence and dysfunctional roles constitute the backbone of the Loman's relationship. It is a relationship that can only be healed by the a reality check, and by the mutual choice of accepting it the way that it is. 

"Death of a Salesman," a classic piece of American literature written by Arthur Miller, tells the story of Willy Loman, a traveling salesman of 34 years who is unable to accept change—within himself, his family, or the society at large. His sons, Biff and Happy, couldn't be more different in their personalities, and it's evident in how they treat their father.

Biff is a deeply flawed 34-year-old, from his inability to hold down a decent job to run-ins with the law. However, he demonstrates a strong desire to mature and grow. He especially looked up to Willy when he was a young star football player; but as he's gotten older, he comes to see his dad's wishes for his life as materialistic and unattainable. Having seen Willy cheat on his mother also tainted the idea of his father as a role model. He now finds his father difficult to communicate with and begins to blame his father for making him arrogant, which he says is the reason his bosses always fire him. He wants his father to simply love him for who he is and feels a need to convey the truth about who he is inside and the problems he feels his father caused.

Happy, on the other hand, is quite different from his older brother, both in terms of his personality and his relationship with his father. He shares his father's deluded sense of over-confidence and dreams of getting rich quick. However, because Willy has always favored Biff, Happy has had to work extra hard to please him. He sticks up for his father and defends him from Biff's tirades. He is desperate for his father's approval and makes that clear in their interactions. Ironically, Happy reveals he's actually become rather despondent about the fact that his life is not working out for him as he planned. Yet he stubbornly clings to the notions his father instilled, and thanks to a misguided devotion to his such principles, continues treating his father as if everything is perfectly fine when it's not.

Willy Loman has mixed feelings about his oldest son, Biff. As an adolescent, Willy hoped to live vicariously through Biff and believed that he could succeed at becoming a successful, wealthy salesman because of his appearance and likability. Tragically, Biff discovered his father having an affair during a business trip in Boston, which ruined their relationship. After discovering that Willy was cheating on Linda, Biff never tried to pass his math course or become a college athlete.

As an adult, Biff struggles to make ends meet and has not lived up to his father’s expectations. Biff’s failures in life make Willy upset, and he believes his son is unsuccessful out of spite. Willy cannot comprehend why Biff would not succeed, refuses to take responsibility for his son’s lack of success, and continually argues with Biff. Essentially, Willy places unfair expectations on Biff and refuses to acknowledge that Biff’s interests and talents are not suited for the sales industry. Overall, Willy loves Biff, yet he resents him for not becoming a successful salesman and believes he has failed out of spite.

Biff appears to be a failure, yet he is not. Willy loves Biff; in fact, he has attempted, as many parents, to live vicariously through Biff. Willy continuously thinks of Biff's glory days in high school as the happiest times in his life. However, Biff is an unsuccessful salesman, unsuccessful in following in his father's footsteps. Ironically, this is critical to the play's theme. Willy also ends up as an unsuccessful salesman after squandering his life in the attempt to succeed, illustrating the corrupt influence of the American Dream. Biff actually goes on to live the real American dream, becoming one with the land, instead of selling his soul as a salesman. Willy fails at all his dreams and can only hope to plant a garden in the stifling atmosphere of the city.

Willy Loman is annoyed with his son because Biff did not fulfill or exceed his expectations of becoming a successful salesman. Willy raised Biff to believe that likeability and appearance were the foremost attributes necessary to achieve the American Dream and climb the social ladder. Willy dismissed Biff's negative behaviors and actually encouraged him to cheat and steal as an adolescent. Willy Loman also believed that Biff would pass his math exam and enroll in college, where he would become a football star. Willy felt that Biff would easily attain success simply because he was attractive, charismatic, and athletic.

Tragically, Biff never lived up to any of his father's dreams and is instead an unemployed thirty-four-year-old man with no family, home, or money. Willy is also upset with Biff because he feels that his son purposely failed at everything in life out of spite. Willy tells himself that Biff purposely failed to make him upset and refuses to take responsibility for his son's lack of success. One could also argue that Willy represses his failures as a parent and projects the negative image of himself onto his son, which is why he is annoyed with Biff.

Willie thinks Biff is wasting his gifts, his personal attractiveness.  Wille based his career on the concept of attractiveness believing that it would be the key to his success as a salesman.   Willie excused all types of destructive behavior (stealing a football, for example) because of his personal attractiveness.  The foil to Biff is Bernard.  Bernard represents the work ethic; he tries to get Biff to study so that he will graduate and be able to accept an athletic scholarship to the University of Virginia, but Willie mocks Bernard, saying that he will never be successful becuase he lacks this personal attractiveness.  Sadly, as with many things, Willie has this all wrong.

 The other possibility is that Willie is guilty because he knows that Biff's downhill slide began when he found Willie in a compromising situation when he travelled to Boston to find him and ask for his help.  It is as though if Biff were successful, this incident would be wiped off the books as it were and return Willie to his one success in life --- as a father.

The conflict between Willy and Biff seems to have developed in the wake of Biff's discovery (when he was very young) that Willy was having an affair. But more fundamentally, the tension between the two is owing to Willy's unrealistically high expectations for his son, and Biff's inability to meet them. Even as he has tried to hide his failures from his son, Willy remains convinced that Biff has failed to achieve success in life just to spite him, and he also believes that Biff has no respect for him, regarding him as a "nobody." Biff, on the other hand, blames his failures on his father, claiming that he filled him "full of hot air" and that trying to be a successful businessman, as his father wishes, is just not for him:

Pop, I’m nothing! I’m nothing, Pop. Can’t you understand that? There’s no spite in it any more. I’m just what I am, that’s all…. Will you let me go, for Christ’s sake? Will you take that phony dream and burn it before something happens?

This outpouring of emotion in the final act, ironically, convinces Willy to commit suicide, believing that his son will idolize him because, through his death, he will provide him with life insurance money. 

Linda and Willy have a complicated marriage, where their real issues are continually overlooked, and their emotions are suppressed. While both Linda and Willy love each other, each character has their own specific way of demonstrating their love. Linda understands Willy's shortcomings but remains by his side as a supportive, understanding partner. She also entertains Willy's fantasies in order to not hurt his feelings and gently brings up serious issues in a way to avoid Willy's violent temper. Linda continually worries about Willy's mental health but is too afraid to confront her husband about his suicidal tendencies out of fear that she will upset or embarrass him. Linda also refers to Willy as "a little boat looking for a harbor" and encourages Biff and Happy to be nice to their father.

Willy does not reciprocate Linda's feelings and finds it difficult to express his love for her. Willy continually loses his patience with Linda and yells at her whenever he gets upset, which is something that Biff criticizes his father for doing. Willy is rather inconsiderate, insensitive, and borderline abusive towards Linda. Willy seems unappreciative of Linda and tries his best to maintain a resolute, optimistic disposition at all times. However, there are times when Willy shows his true feelings and confides in Linda. He also feels guilty for cheating on her with the Woman in Boston, which is why the memory continues to haunt him.

Both of Willy's sons disrespect and degrade women in the play. As an adolescent, the girls at school complained about Biff being too aggressive with them, and Happy carries on numerous affairs with the wives of his bosses. Given Willy's infidelity and unfair treatment of Linda, one could argue that Biff and Happy were negatively influenced by their father to use women and treat them disrespectfully. Willy never corrected their behavior as adolescents, and Biff and Happy grew up to be immature, inconsiderate men. Biff and Happy seem to share their father's outlook on women and treat them as convenient objects, which reflects Willy's treatment of Linda.

Answering this question requires considering the drastic difference between these two characters and the fact that they only meet in Willy's hallucinatory flashbacks, not in real life. Let's start there: Ben and Biff never had a "real" relationship. However, the play does definitely place these two characters into a symbolic dialogue with one another. I'll clarify some key points about each character first; then we'll look at how the two relate.

Biff is Willy's oldest son. Biff's defining feature is his struggle between who he is and who he's been raised thinking/believing he should become. His father's fixation on a successful run in business and the belief that one must be "well liked" have created in Biff a strong sense of being lost. However, we also hear a lot from Biff about how he'd rather be outdoors, with his shirt off, doing manual labor. He has no knack for business, though he feels guilty for never being able to succeed in that lifestyle, especially since he utterly idolized Willy up until his last year of high school.

Rather than a flesh and blood character, Ben is really more of a symbol, signifying Willy's vision of ultimate success. Ben's famous recurring line is "William, when I walked into the jungle, I was seventeen. When I walked out I was twenty-one. And, by God, I was rich!" (eNotes Death of a Salesman character analysis). This is what Willy wants for his boys, especially Biff--to be able to walk into the "jungle" (let's infer: New York City is often referred to as "the urban jungle") and come out rich in a short, effortless amount of time, which is true success in Willy's eyes.

We can think of Ben as representing what Willy hopes for and pressures Biff to become. Biff, meanwhile, tries to emulate this idea, but finds that it ultimately kills his soul. We see this idea play out in Act I, when (within Willy's hallucination) Ben cajoles high school age Biff into boxing with him. Suddenly, Ben takes a cheap shot and "Trips Biff, and stands over him, the point of his umbrella poised over Biff's eye" (Miller 49). Of course, Biff is surprised by this. Ben explains his sudden violence with "Never fight fair with a stranger, boy. You'll never get out of the jungle that way" (49). If we look at this symbolically, we see that Biff is told he must trade his integrity for success in business. Also, we get the feeling that interacting with Ben (who stands for Willy's vision of what Biff should become) could be potentially harmful, violent, and maybe even deadly for Biff. Biff himself knows he can't make it out of the symbolic jungle, as he finally admits to Willy in Act II:

"What am I doing in an office, making a contemptuous, begging fool out of myself, when all I want is out there, waiting for me that minute I say I know who I am?" (132).

Biff struggles and breaks free of the ghost of Ben's example in this final confrontation with Willy. In contrast, it's the ghost of Ben's example that convinces Willy to commit suicide to provide some capital for the business ventures that Biff will never actually pursue. While Biff can ultimately say that he doesn't want to become Ben, Willy cannot accept that, and clings to the idea until his death. One could argue that Ben's final reference to Biff, calling him "outstanding, with twenty thousand behind him," is really the voice of Willy.

Miller, Arthur. Death of a Salesman. New York: Viking Press, 1968.