Evolutionary biologists, would love to tell you that we(both men and women) are designed to cheat in order to fulfill our primary goal in life of passing on our selfish genes with a partner most likely to produce healthy offspring.
Romantics will say that true love conquers all, and that when you find that special person, harps will play, Doves will sing and you will never again want to bang that hot chick at your office.
The truth as with most things in life, lies somewhere in the middle.
It's my opinion that EVERYONE is looking to trade up sexually. This is where I firmly believe in evolutionary biology, as well as the added social and sexual benefits of having a more attractive partner. It's not just women or club girls or men or high status high powered men. It's everyone. Somewhere there is a redneck whose wife is 250lbs, who is cheating on her with a 200ILB woman and feels great about the upgrade.
the reason people dont cheat, is the physical and social consequences. stds and being found out.
So really we kinda gotta accept it but use this as motivation to be the best alpha male that we can be. russell brand or brad pitt wouldnt get cheated on cos there is no one that a girl could "upgrade" with.
there are obviously girls that dont go clubbing and have religious morals and ethics. but even they do have a desire to mate with the most alpha mate.
here are things to work on:-
1. Emotional fulfillment. This means that a woman's full range of emotional needs from empathy to jealousy and helplessness are met by you.
2. Sexual fulfillment. This one is the most self explanatory. You have to make sure she's having regular orgasms, and you have to keep your sex life interesting.
3. Intellectual fulfillment. I'm not saying you have to be a Mensa member or anything but you do need to fulfill whatever the woman's intellectual needs are.
keep those in check and keep building your value and you stay in good shape not to just keep your girl madly in love with you but also to trade up yourself if you want. Btw I dont cheat myself, been down that road and just leads to massive headaches and it does affect your self-esteem. most of the above is ala sinn so enjoy and accept.