For a female perspective on this - women are turned on by monogamous men. Monogamous men are able to satisfy their partner and this leads to a lifetime of wonderfully fulfilling intimacy.

A man who has to run around dipping his wick wherever, is usually a pretty shallow excuse for a man, he isnt able to commit 100% because he knows he is lacking in one department or another, and needs to get reassurance from equally shallow women who also need reassurance for their inadequacies, if he thinks scoring with the local bike is manly, he is not only wrong, but laughable.

Monogamy is sexy.