What literature is there on women having affairs even though they say there happy with the man they love?

There is a body of literature on infidelity in relationships that explores why some women may engage in affairs despite being in a seemingly happy relationship. This research often examines factors such as emotional needs, lack of fulfillment, communication issues, or seeking excitement or attention outside of the primary relationship. Studies suggest that infidelity is a complex behavior influenced by a variety of individual, relational, and situational factors.