The Graduate

In the 1960s, Benjamin Braddock, aged twenty-one, has earned his bachelor's degree from Williams College and has returned home to a party celebrating his graduation at his parents' house in Pasadena, California. Benjamin, visibly uncomfortable as his parents deliver accolades and neighborhood friends ask him about his future plans, evades those who try to congratulate him. Mrs. Robinson, the neglected wife of his father's law partner, insists that he drive her home. Benjamin is coerced inside to have a drink and Mrs. Robinson attempts to seduce him. She invites him up to her daughter Elaine's room to see her portrait and then enters the room naked, making it clear that she is available to him. Benjamin initially rebuffs her, but a few days later after his scuba demonstration on his birthday, he clumsily organizes a tryst at the Taft hotel.
Benjamin spends the remainder of the summer drifting around in the pool by day, purposefully neglecting to select a graduate school, and seeing Mrs. Robinson at the hotel by night. He discovers that he and Mrs. Robinson have nothing to talk about. However, after Benjamin pesters her one evening, Mrs. Robinson reveals that she entered into a loveless marriage when she accidentally became pregnant with Elaine. Both Mr. Robinson and Benjaminâs parents encourage him to call on Elaine, although Mrs. Robinson makes her disapproval clear.
Benjamin takes Elaine on a date, but tries to sabotage it by ignoring her, driving recklessly, and taking her to a strip club. After Elaine runs out of the strip club in tears, Benjamin has a change of heart, realizes how rude he was to her, and discovers that Elaine is someone with whom he is comfortable. In search of a late-night drink, they visit the Taft hotel, but when the staff greet Benjamin as "Mr. Gladstone" (the name he uses during his rendezvous with Mrs. Robinson), Elaine correctly guesses that he has been having an affair with a married woman, and accepts his assurances that the affair is now over. To preempt a furious Mrs. Robinson, who threatens to tell Elaine her version of their affair, Benjamin tells Elaine that the married woman was her mother. Elaine is distraught and returns to Berkeley. Benjamin pursues her there and tries to talk to her. She reveals that her mother's story is that he raped her while she was drunk, and refuses to believe that it was in fact Mrs. Robinson who seduced Benjamin. After much discussion over several days, Benjamin begins to talk her around. Mr. Robinson arrives at Berkeley and confronts Benjamin at his rooming house, not knowing whether he can prosecute him, but he thinks he can and threatens to put him behind bars if he sees his daughter again. Mr. Robinson then forces Elaine to drop out of school and takes her away to marry Carl, a classmate with whom she had briefly been involved.
Returning to Pasadena in search of Elaine, Benjamin breaks into the Robinson home but encounters Mrs. Robinson. She tells him he will not be able to stop the wedding and then calls the police, claiming that her house is being burglarized. Benjamin visits Carlâs fraternity brothers who tell him that the wedding is in Santa Barbara, California that very morning. He rushes to the church and arrives just as the bride and groom are about to kiss. He bangs on the glass at the back of the church and screams out "Elaine!" repeatedly. After a brief hesitation, Elaine screams out "Ben!" and starts to run toward him. A brawl ensues as guests try to stop Elaine and Benjamin from leaving together. Elaine manages to break free from her mother, who then slaps her. They run into the street to flag down a passing bus and take the back seat, elated at their victory. Benjamin's smile gradually fades to an enigmatic, neutral expression as he gazes forward, not looking at Elaine. Elaine first looks lovingly across at Ben but notices his demeanor and turns away with a similar expression as the bus drives away, taking the two lovers towards a future of uncertainty.

Question: What is the name he uses during his rendezvous with Mrs. Robinson?
Answer: Mr. Gladstone