In Chapter One of The Great Gatsby, why does Nick feel "confused and a little disgusted" after he leaves Daisy's house?
While Nick is having dinner with Tom, Daisy, and Jordan Baker at the Buchanans' home, they are interrupted by a telephone call that Tom takes privately. Daisy suddenly leaves the table, too, and Nick can hear them talking in "[a] subdued impassioned murmur." Jordan explains the situation to Nick: "Tom's got some woman in New York . . . . She might have the decency not to telephone him at dinner-time." It takes Nick a moment to realize what Jordan is telling him, that Tom is having an extra-marital affair. From her reaction, Daisy clearly knows what's going on. The telephone rings again, but Daisy sends Tom a clear signal not to answer it and an uncomfortable silence ensues. When they are alone, Daisy tells Nick how unhappy she is, without mentioning specifically what has just happened. The evening then continues, as if nothing unusual had occurred.
Nick leaves the Buchanans feeling "confused and a little disgusted." He is shocked by Tom's behavior, but he is also shocked and confused by Daisy's reaction to Tom's infidelity: "It seemed to me that the thing for Daisy to do was to rush out of the house child in arms--but apparently there were no such intentions in her head." This encounter is Nick's first exposure to the immorality and amorality that he will observe in the East throughout that summer, behavior that is very much at odds with his Midwestern upbringing.
As the other educator has stated, Nick has just found out that Tom Buchanan is having an affair and that his wife, Daisy, knows about it. Nick is "confused" and "disgusted" because he does not understand why Daisy has not left Tom, as we learn from the next lines:
"It seemed to me that the thing for Daisy to do was to rush out of the house, child in arms."
While Nick is not that surprised to learn that Tom is having an affair, he is struck by Daisy's acceptance of the situation. In fact, his view of Daisy has changed significantly after spending time with her at dinner. He is shocked by her "insincerity" when she confides to him in private about the state of her marriage more generally, like the fact that Tom did not attend their daughter's birth.
Nick, then, is beginning to see beyond the facades of Tom and Daisy, and this is what leads to confusion and disgust.