Nick is the first-person narrator inThe Great Gatsby. In Chapter 1, Nick establishes himself as an honest person (and a reliable narrator). He is a good judge of people but he is not judgmental.
In consequence, I’m inclined to reserve all judgments, a habit that has opened up many curious natures to me and also made me the victim of not a few veteran bores.
In Chapter 2, Nick accompanies Tom to George Wilson's garage, located in the "Valley of Ashes." Nick and Tom then meet up with Myrtle at an apartment in New York City. Since Nick is a reliable narrator and an honest person, we can trust his observations. Nick already doesn't trust or like Tom so he's not exactly surprised when Tom wants him to meet "his girl." Myrtle treats her husband like dirt, passing him like a ghost when Tom arrives. Later, she will admit that she thinks she married below herself.
"I married him because I thought he was a gentleman,” she said finally. “I thought he knew something about breeding, but he wasn’t fit to lick my shoe.”
This occurs during a discussion where Mrs. McKee claims she'd almost married a "kyke" who she knew was "below" her. Nick describes Mrs. McKee as "shrill, languid, handsome, and horrible." Nick describes Mr. McKee as feminine and respectful, perhaps an allusion to George Wilson, both married to domineering women.
Nick notices that Myrtle's attitude changed when they got to the apartment. She was no longer the wife of a failed mechanic living in an apartment in the Valley of Ashes. She was now a sophisticated woman spending time with upper class friends in New York City.
The intense vitality that had been so remarkable in the garage was converted into impressive hauteur.
Catherine is a gossip. And of course, Tom is his usual brutal, macho self. The culmination of Nick's evening with this superficial crowd is when Tom breaks Myrtle's nose for mentioning Daisy's name.
The most sympathetic character in this chapter (other than Nick) is George Wilson. His wife, Myrtle, is with Tom so she can get a taste of the good life. For Nick, the behavior of Tom and Myrtle (and certainly Mrs. McKee) is despicable. Remember that Nick prides himself on being a good judge of people but not prejudging them. These three people (Tom, Myrtle, and Mrs. McKee) mostly express elitism, indifference, and superficiality. Nick is right to criticize them. If we learn anything new about Nick, it's that he is quite perceptive as well as being honest.
One of the words Nick uses to describe Tom, in chapters 1 and 2, is supercilious, which means Tom behaves as though he thinks he's superior to others. Myrtle behaves this way as well, especially in the apartment.
One of the reasons Nick connects with Gatsby is because he recognizes a small-town naivety about him. Nick, although not naive, has a similar small-town humility about him, which is why he finds elitists like Tom so deplorable.