Men Cheat for Sexual Reasons, Women Cheat for Emotional Reasons
The most frequently cited reasons for infidelity among men include:
more sex (the desire for a more active sex life)
sexual variety (a desire for different kinds of sex)
opportunistic sex ( taking advantage of an opportunity to have sex without the fear of getting caught)
to satisfy sexual curiosity (about a specific female)
a feeling of entitlement (the belief that it’s a man’s prerogative to cheat)
the “thrill of the chase”
the desire to feel important or special
sexual addiction
Cheating Husbands and Cheating Wives Give Different Reasons for Having Affairs (article) by Ruth Houston on AuthorsDen Cheating man - AskMen.com