I've read some reviews of Jenny Sanford's book, "Staying True." It seems that, beginning with their courtship, Mark Sanford was abusive. Ruth Marcus has catalogued some of his transgressions here. So, given Mark's mistreatment of her, culminating in his redefinition of "walking the Appalachian Trail," why did she bother to marry and stay with him? The answer is simple: Jenny Sanford is a "bad girl" because she has sex, even with her husband. Therefore, she feels she must be treated as such. I saw a lot of this in college: American women dating and even marrying abusive men. I'll give two examples that stick most prominently in my mind. The first was a woman who had been appointed to the Student Government Senate. Three men proceeded to ask her disrespectful questions and generally act like jerks to her. I apologized for their conduct and asked her a serious question. Later, I saw her clinging to one of her tormentors. On another occasion, a man bragged about his sexual exploits in front of his girlfriend. Rather than take offense, she clung to him with a big smile. She seemed to be expressing, "Isn't he wonderful?"
The idea that only "bad girls" have sex is an example of American sexual repression. It is not without reason that Irene Kassorla wrote "Nice Girls Do." This was one book I did not need to read. After all, how could any process that produced me be bad? BTW, I've never had an American girlfriend.