Although research has illuminated some differences between those who engage in sexual behavior outside of their marriage and those who do not, there is a lack of attention in the literature to complex interactions among variables in their relationships to infidelity. There is evidence that marital satisfaction, sexual satisfaction, and personality are all related to infidelity but research has failed to investigate how personality may influence these other two variables in their relationship to infidelity. Thus, the proposed study explored possible effects that selected personality factors have on the relationships between marital satisfaction, sexual satisfaction, and infidelity. The results revealed that decreased marital satisfaction and decreased sexual satisfaction were both associated with an increased likelihood of infidelity. Of the personality factors privateness, rule-consciousness, and sensitivity, none were directly associated with infidelity. However, privateness and rule-consciousness both were found to be moderators of the relationships between sexual satisfaction, marital satisfaction, and infidelity.