Joris Lammers of Tilburg University in the Netherlands surveyed 1561 professionals who identified themselves as having similar careers and similar amounts of power and compared their infidelities based on gender. While it has long been believed that men cheat more, when women are just as successful as their partner (and hold powerful positions) they are just as likely to cheat. The researchers conclusions: powerful people cheat on their spouses, regardless of gender.
They even go further to explain the reason by they think power leads to infidelity (are we listening partners to executives, politicians, professional athletes etc)...power leads to confidence, and confidence leads to sex. While not phrased exactly like this in Psychological Science, a journal of the Association for Psychological Science where the press release regarding the study appeared, they did say "First, there is a strong association between power and confidence and that the amount of confidence a person has is the strongest link between power and unfaithfulness. Second, the researchers found that among powerful people gender made no difference in past digressions or the participants’ desires to cheat."