Keep telling the authorities, even when they don't want to hear!! If the woman is doing that to the little boy, she should be put away. Encourage him (without at all coaching him) to tell the doctor what is happening. His trust in adults who are supposed to care for him is probably faltering due to the stepmom abuse/dad not protecting him. Let him know that no matter what the truth is, thats all they need to hear from him, and YOU love him no matter what, no conditions. You are not about his dad or his mom, just HIM. Take care!
Shelly