Curley is an insecure, combative person who likes to pick a fight. When he first meets Lennie and George, Curley says, "Let the big guy talk" (when George continues to speak for Lennie). Curley seems to be itching for a fight, and he dislikes Lennie because Lennie is a big guy. Curley, a small man, feels inferior because of his small stature. He wears a glove and coats his hand with vaseline to keep it soft for his wife. Curley clearly worries that his wife might not find him attractive.
One of the ranch hands says of Curley's wife, "she got the eye." Even though she was just married to Curley, she is flirtatious with other men on the ranch. She is also constantly stopping by the bunkhouse, ostensibly looking for Curley but really looking for attention. She enjoys attention, and she later shows up at the bunkhouse wearing red mules topped with ostrich feathers. She is heavily made up and paints her nails red, and she clearly likes to receive attention from men and is lonely as the only woman on the ranch.
Curley and his wife have a very turbulent relationship in Of Mice and Men.
Curley is possessive regarding his wife. He shows this in chapter 2, when he is repeatedly asking if anyone knows where his wife is. He suspects many of the ranch hands when it comes to his wife, including Slim. When talking to George, Whit suggests there might be a sense of turbulence between both husband and wife. He speaks about how Curley is quite anxious about his wife, saying that Curley has "yella- jackets in his drawers." At the same time, we can presume that Curley does not treat his wife well when he is with her. When she is talking to Lennie, she tells him that Curley's "not a nice fella." The way she says it reflects personal knowledge about what he is capable of doing. It is evident there is not much in way of happiness between them.
Steinbeck does not depict the couple in anything resembling a healthy relationship. Whit perceptively says that both of them are akin to two ships passing in the night: "He spends half his time lookin’ for her, and the rest of the time she’s lookin’ for him.” Both of them are not shown as being emotionally settled with one another. This reflects how Curley and his wife do not find much in way of happiness in their relationship.