He does not seem to care about her feelings but rather her body. " Yvette wanted to wait, but Duddy insisted, and they made love on the carpet." This quote clearly shows that emotions are not involved in this relationship, at least not on Duddy's part. He does not respect Yvette, this partly due to the fact that he does not know how to treat a woman. .
One of the reasons Duddy does not care about Yvette is because he does not care about anything. He was brought up with a drunken father and the only reason his brother, Lenny, is doing so well in life is because his Uncle Benjy took him under his wing. Duddy was not used to being around women at all. He did not have a mother figure while he was growing up, and was not taught to respect women or treat them a certain way from his father. His father pimped women and in a way Duddy learned from this example. When pimping a woman, the pimp uses the girl to get money. Duddy used Yvette to get his land as well as sexual favors. I do not feel that Duddy intentionally wants to hurt or disrespect Yvette. To the best of his knowledge, he probably does not see anything wrong with the relationship that he and Yvette have. He is ignorant to the "right" way to treat a woman.
Yvette is probably just as much to blame for the relationship that she and Duddy have. She knows that she is being used and she is forced into doing things that she does not always want to do. She could easily leave the situation right away and refuse to help Duddy. Especially after the way he treats her sexually. Duddy is blind to the fact that he is unkind to Yvette, however Yvette can see how she is being treated and continues to pursue the relationship. She knows that they will not get married because of the religious differences and she is just wasting her time with him, yet she stays.
In "Surfacing" we see a similar relationship with the narrator and Joe. At the beginning of the novel the narrator is content with Joe being around, however we know right from the start that she does not love him, but that he loves her.
