Women will never be satisfied with a small penis. If you are under 7 inches, your wife is going to cheat on you, period.
Why are you saying that women can never be sexually satisfied with a man who has a small penis?
When women find out you have a small penis, they're going to cheat on you.
It's possible that you've been unlucky in your relationships and your partners have cheated on you for other reasons, you have to really examine your past relationships. Most women are in a relationship because they love many aspects about their partners. If they are unhappy and cheat, it is usually for multiple reasons, not just sex.