What are the effects of infidelity on the lives of the majors characters in The girl in their summer dresses?

In "The Girl in the Summer Dresses" by Irwin Shaw, the effects of infidelity on the major characters are primarily emotional and psychological. Michael's infidelity causes Frances to question their marriage and her self-worth, leading to feelings of betrayal and insecurity. It also causes Michael to confront his own feelings of guilt and remorse, impacting his sense of integrity and commitment. Overall, infidelity disrupts the characters' sense of trust, intimacy, and connection in their relationship.