This is very, very serious. You say the boundaries have been blurred for quite some time. Maybe what you are interpreting as jealous and provocative behaviors are your daughter’s efforts to tell you in the only way she can to wake up! Your husband is not drawing appropriate boundaries. It may be that he has been molesting her. It may be that he has threatened or bribed her to keep quiet about it.
You keep talking to the two of them as if they are equals in the situation. They are not. She is your child. He is a man who is supposed to be keeping her safe. He may be justifying his behavior on the grounds that he is not related biologically to her but he is her stepfather, not her boyfriend. One slip in the boundaries is perhaps a “mistake.” More that once? Please! You are in serious denial.
Your daughter needs help, not talk. In your state, sexual abuse is defined as when a parent or other adult uses a child under age 18 for sexual gratification. Your husband should be reported to Child Protective Services at 855-GA-CHILD . That’s easier said than done, I know, especially since you feel dependent on him. For that reason, I suggest you first call your state’s 24-Hour Statewide Domestic Violence Hotline, 800-33-HAVEN. Although you may not think of yourself as being a victim of domestic violence, your daughter certainly is. The counselors at the hotline can help you figure out how to keep everyone safe and how to manage without your husband, should that be necessary.
All of you — your daughter, you, and your husband — need counseling. Your daughter needs help sorting out what has been a confusing and abusive situation. If she has been manipulated or “brainwashed” to think her stepdad’s behavior is OK, she is especially vulnerable. You need emotional support as well as some practical help to keep your family secure and afloat during a difficult time. Since you husband can’t keep his hands to himself, he needs to leave until he has done some serious personal work. He must take responsibility for his behavior and he has to learn impulse control before he can be part of the family.
Please don’t let your fears prevent you from taking action. Your daughter, and your other children, need a tiger-mom right now. They deserve to feel safe from sexual abuse in their own home. If your daughter is to have a chance for a normal relationship with a partner someday, she needs you to get the family the help you all need.
I wish you well.