You might presume that the men who give up work to look after the children are more dedicated to the family unit. However, according to a new study, they are more likely to have an extramarital affair than the men who remain the main breadwinner after childbirth.And the greater the earning gap between the stay-at-home dad and his working wife the greater the chance that he will be unfaithful.In contrast, the more financially independent the woman the less likely she is to have an affair.The women who earned 100% of the family income were the most faithful of any of the groups studied.Study author Christin Munsch suggested that financially dependent men's wandering eyes are a reaction to their emasculated role in the household."Extramarital sex allows men undergoing a masculinity threat - that is not being primary breadwinners, as is culturally expected - to engage in behaviour culturally associated with masculinity," she said. ..