I just found out about this concept today.

A link to a page about it: 

http://bpdfamily.com/content/was-part-your-childhood-deprived-emotional-incest

And let me be clear - this doesn't have anything to do with sex, or sexual abuse, at least in my case. Nothing like that. It's like... an inappropriate emotional dynamic. I always used to say that my (uBPD) father and I had an atypical relationship, and now I see why. I suppose I didn't want to see just how fucked up it was, given that it was me basically supplementing the fact that my dad didn't have a romantic partner (my mom died)or any friends.

Now, I'm 29, and back living with my dad due to unfortunate circumstances, and the dynamic has been in full swing ever since. It's been made worse by the fact that my dad now has another child, from a sociopathic woman who doesn't want to be involved, and so I have been the designated surrogate parent. Since the emotional/biological attachment is there, I feel bad about the prospect of leaving my brother to the wolf, but I have to get the fuck out of here.

The worst part is, after learning about EI, I don't even know if my suspicion of being Borderline is correct anymore. Maybe I'm just reacting to my dad's behavior. And I'm so used to the dynamic that I feel like I can't even constitute myself as a victim, anymore. I'm also 30, and I'm an active participant in it. 

I'm disgusted, angry, sad, stressed. And I'm so dependent on my dad now, that I can't find where my first step is to get out of this hole.

Anyone else dealt with this?