Oh, Buddybear, that's tough. I am both a stepchild and a stepmother and found your description of your boyfriend's daughter to be "normal" for children her age and in that situation and very much my experience.

I often got "between" my father and stepmother when they were trying to kiss hello when my father returned from work in the evening (I was younger at the time). I think if you were there permanently, behavior such as your boyfriend's daughter exhibits would decrease over time. I think right now, with her father and mother split and you only a "girlfriend" there's going to be a lot of uncertainty and jealousy no matter what you say, especially if your boyfriend does not discourage or comment on certain behaviors. I don't think working with the daughter right now can help much as one doesn't know the mother's input and the father has none. . . They're still 100% of her world and you are still only an occasional add-on. If you lived with your boyfriend, moved/rearranged the apartment, etc. so it had "you" as part of it, then you might slowly make headway but the daughter has no reason to listen to you and gets more of what she wants by not?

I was living with my husband, in our house when his son, about the age of your boyfriend's daughter behaved very much as you describe his daughter behaving. When we were a "threesome" my stepson would monopolize his father and I would be kept waiting, ignored, etc. I began encouraging the two of them to spend time alone but then, I had my husband/boyfriend-at-the-time to myself the rest of the week.

I think you will have to talk to and come to some sort of agreement with your boyfriend so you get some time to yourselves. However, if he doesn't want that, then I see trouble ahead? If the situation can't be made more "normal" where his kids know their father is available as "needed" then I think they'll continue to test that. Once my husband and I married and had the son over "whenever" and I got a solid relationship with he and his brothers so we were "just" family, like all the rest of it (and became good friends with the ex-wife) a child wants/needs more "care", especially when not in their "home" (with their mother) environment. Think about how you would like it if you went to a party where you knew/cared about only one of the hosts and were stuck there for X period of time, without choice?