why does myrtle behave with such arrogance both toward aher husband and in the city apartment?

Although she is married to Wilson, she seems to care little that he is aware of her affair with Tom, who is richer and more "elegant" than her husband. She acts with arrogance because Tom is from a different social class, yet he often does put her in her place. However, the affair can go on in New York City without anyone really caring.