WOW, I'm so sorry your going through this.
Let me say that in the comments I am about to make, I am NOT commenting on your husband because I don't know him.
I have heard that when children are abused, they do not necessarily FLEE the person who abused them. I have a friend who was sexually abused by her Father. She never dealt with it in fact didn't even remember it until I told her I had to type up a police report about her Father in my job as a police dispatcher. He had been arrested for sexually abusing a child in a larger town near us. She passed this information on to her Mother who later told me that she felt he had done this to my friend AND that over the years another child had come to her to say that he had done the same thing to her. She left him immediately. He had been a minister and had access to ALOT of children over the years.
This friend came to me a couple times that summer to talk about it and then later never remembered the conversations. To this day 20 years later she has no memory of these details. She allows her Father into her home, around her own children as if nothing happened. She even asked me to come down and bring my daughter with me to visit him when he was in town. I wanted to say something but I just declined the offer.
Its very posible that your stepdaughter was abused but by someone else. She sounds sort of boarderline personality disorder in the way you describe her and sexual abuse as a child can preciptate this disorder. That doesn't mean your husband was the one who did it however. It could have been anyone, another family member, a neighbor, a teacher. He could feel quilty that he wasn't there to stop it as any parent would in wanting to protect their child.
The reality is however, she is a grown woman and as such is responsible for her own mental health. I think its a good idea to give people like this boundaries and tell them, get some help, or you can't be part of my life, I will join you in a session if you need but I will not have you tearing apart my life in this destructive fashion.
People who are mentally ill often don't have boundaries, they don't understand that they have gone too far AND they have little or no insight into how out of control and innappropriate their behavior is.
It would be insightful to understand what her relationship is like with her Mother and any other men in her life. If she has been sexually abused, its likely she isn't able to sustain a sexual relationship with a man since it sounds like she hasn't gotten help for the abuse.
