Agree with the above posters.
Whatever this child does she has learned from the father and apparently this is normal for these two. They aren't going to change and this is not what you are looking for.
Leave this one.
Hey I think the best thing you should do is just leav and find someone who don't have a kids.. believe me it will get wores I whish If I can leav but mine is too late I alrady have a baby with him and he have 11& 7 years old girls before when I meet him I didn't think it will get worest !! So just move on and don't look back u don't need to be hurt !!!there are alots on man out there !!:;
Thank you for your comment I have left & stayed friends but getting on with my own life .
It sounds to me like his daughter is just needy, and seeks a lot of attention from her Dad. I wouldn't say that is ANY indication that there's some kind of sexual abuse or anything inappropriate going on. Now, I agree with you to an extent that at 12, and with the changes her body is making, it would be helpful (for her) if Dad would gently explain that there should be some boundaries. He should not only be fostering her emotional needs, but also encouraging her to be more independent, doing more for herself.
The overall relationship issue though, is pretty straightforward. You cannot change other people, and it would not be wise to stick around hoping things will change. They indeed MAY change, but not at a pace you're comfortable with. This is one advantage to dating people before getting involved in a more serious commitment...you can find out if there are things that are deal breakers. This sounds like one for you.
It sounds like you've left the relationship, which I'd say was probably the best move. I would encourage you to move on at this point, as his relationship with his daughter is no longer a factor in your life.
Good luck to you, hope you find someone you're more compatible with!