Where am i in this situation with my bf and stepdaughter?

You won't be able to adopt her. Unless there are some extreme cirstances on the mothers side and she is deemed unfit to care for the child. Usually the mother has majority of the rights. However it depends on each situation. How long has the child been living with the father. If she has been living there for most of her life. more then likely he would be granted custody with the mother still having visitation set up by the court. Generally every other weekends, set holidays, ans part of the summer. This is how they do it for men who have been granted visitation. If the child has been with the mother most of her life then you can just reverse the situation.