Early in the movie, when Mrs. Robinson is in Benjamin's bedroom, she asks for an ashtray. Then she notes that of course he wouldn't have one, seeing that Benjamin's a track star, implying Benjamin Braddock doesn't smoke.. However, later in the film, just after Ben calls Mrs. Robinson to have her meet him at the Taft Hotel, we see Benjamin exit the telephone booth with a cigarette in his hand. He can be seen smoking another cigarette in at least one other scene later in the film.

"Are you hear for an affair, sir?"