He would perhaps be well advised to recognize our incapacity for objectivity. The way things are percieved to be now with gender relations is only partially a product of human nature. Our behavior is largely constructed by our social environment as well. The way we behave, present ourselves, percieve, and desire, are all formed to an extent by our specific culture. It would be difficult to make concrete statements about the difference between the ways men and women approach the idea of fidelity because of all those variables. I do find it a bit frustrating that we tend to give so much authority to our transient moral and social laws.