My experience with BPD was a little different, but that's because the BPD person is my mother so the relationship is different. That said what others have described is right on the mark I've seen those behaviors out of my mom with her ex-husband. He was either an angel or the devil, never in between for her. With me I was the security blanket and if I didn't behave as such I would be treated as if I didn't matter nor exist to her. Prior to her getting married, when I was in maybe 11 or 12, I remember one time she broke up with one of a very long string of boyfriends and didn't want to sleep in her bed alone so she demanded I sleep in her bed with her. She snored and had a waterbed and I just didn't like sleeping in it. One night I snuck out of her bed and went for my own...she acted as if I had done something worthy of disowning me and treated me like I didn't exist for a week unless she was chiding me for something or directing me to something for her, then all of a sudden it was like nothing happened. Very confusing for a kid, but I learned to adapt to her behavior...err I guess that would be maladapt, but whatever. She's still like that, but now that I'm older (33 :what

I'm very careful at setting clear and firm boundries with her and that helps in avoiding her undesirable behavior much better.