I can't give you any numbers but it's my opinion that women are getting away from the old "good girls don't do things like that" mentality. I think men are still more likely to have affairs because they have more opportunities but as more and more women leave the home and join the work force, they are afforded more opportunities to have affairs and their numbers are increasing.
Some years ago I was between marriages (first and second) and I dated a career woman (divorced with no children) who's attitude was that if men can be studs, women can be studettes. She felt that it was her right to pick and choose who she had relations with and under what circumstances and she absolutely refused to be labeled for this. I'm not advocating promiscuous sex but the fidelity rules should apply to men and women alike.
