My relationship in a nut shell

My BS 16.5
My BD 15.5
His D 12
Met SO in summer of 2013, we seen each other EVERY weekend, typically he would come to my house with his daughter EVERY weekend (our homes were about 1 hour apart). My children see there dad every weekend usually Saturday but always come home to sleep, (ex rents a room in a house)

SO moved into my house beginning of 2014, he continued the 2 hour round trip every Friday and Sunday so she could spend the weekend with us.

I raised my children to be polite, to help each other and try your best at what ever you do. They also help out around the house with weekly chores and at times need to be prompted to help out with some things. But when asked will do it.

SD had an older step sibling when she lived with her parents but that sister lived with her dad. Mom was a bar tender and worked nights and weekends. I don't think SD had a great upbringing at home. She did not learn to say please or thankyou, never had any chores, and learned that if she cried and threw a tantrum her dad would give her what she wanted to calm her down.

When we first met maybe the first month or so, she was nice to me, she would pull me a side to have my one on one attention. Then it turned into he is my dad, would try to sit between us, if he or I put arm around each other she would try to physically remove it. She also wanted ALL of my daughter attention. My niece (17) had spent at least 2 weekends a month at out house but slowly anytime my niece came over the SD would tell her dad that they were ignoring her. Kids need space so yes my daughter would want her own time with my niece again my daughter is 15 niece 17, his daughter is just turned 12 a month ago. Anytime my niece came over even for a night SD would cry to daddy, 2 times he actually left for the weekend with his daughter to his mother because he could not take it. It was unfair to his daughter that my daughter enjoyed her alone time with her cousin, please keep in mind they did include her in some things just not everything. SD would make up stories painting a picture that niece was not nice to her. in my house hold be would have bday parties on a sundays and family and friends would come. Her birthday last year she said she did not want cousin to come, I explained that was fine. But if we excluded her I would have to exclude her mother my sister, which would mean I could not invite my other sisters and their families, because it is not right to not invite one and invite the others. She still chose not to have niece come. So her party was her dad her grandmother and myself.

We have gone on family vacation which she has totally ruined, because she would not do anything if it was not her idea, and her dad did not make her. it was awful.

His daughter has spent every weekend every holiday and every school vacation with us. Which in turn meant that my SO and I never do anything together. I have brought this to his attention at least a handful of times, but he has never acted on the clue. Maybe we could at least do a dinner date or movie night alone. NEVER happens

Last fall DCF got involved because SD told school her mom had been drinking and drove her in the car. SO got temporary custody. I though great this will help put a visitation to schedule into place where we might at least have every other weekend alone. Nope mom give full custody to dad, and has only seen SD once in 9 months.
SD resent me I feel because of my relationship with my kids and ex,
she tries to annoy me by playing her iphone loud when I ask her to turn it done she turns it down one notch. She will NOT doing any chores and SO tells her she needs to help BUT never enforces it. My children are resenting this as they see it, and I just tell them I am raising them to be well rounded and I expect them to be helpful. Example other day my son and daughter where moving sons room around when SO comes home and asked his daughter why she wasn't helping her response was I never do. Wouldn't this prompt you to explain the importance of working together as a family. Dad just lets it go.

After 9 months of her living here fulltime I can not take it anymore. My SO and I never do anything alone, I have told him on several occasion we do not have a relationship. Every time we do something it is SO, myself and his daughter. My kids are either home doing their own thing or off with dad. Typically we go to breakfast
it is always those 2 walking together with me in the back like a 3rd wheel, again I have told him this. She cuts me off if I try to walk with him. A month ago we were invited to a wedding which was my daughter was in , and my son was invited to as it was their half brothers wedding. My SO was invited and he asked if his daughter was and I said young children typically are not invited. I thought finally anight alone with him, as my kids would be off with their half siblings and cousins. We even staying over night, I suggested his daughter stays with his mother. But no he puts my step son on the spot and ask if his daughter can come. So now my night alone, is ruined she sits between us at the wedding we share our room with her, the again when we go for breakfast they walk side by side and I am left to trail behind. Then on the way home she continues with her rude behavior towards me. If I say black she says white. When we got home I lost it and said I can not do this anymore, I can not come home every day to her attitude, I was really done. But now she is on her best behavior, for the past month. But I don't think I can do it, its been a month and I can not let the resentment go. He has and always will put her before me. I understand she is his daughter, but I am his SO, and he allows her to trash me, She was suppose to apologize to me because she acknowledge that she trys to get on my nerves by dong things to upset me. He asked her to apologize but she refused to and he did not make her. She said she is not ready.
Last weekend we had another wedding and he chose to not go with me
cause he did not really know the bride and groom so he stayed home with his daughter. Again I feel he should have gone with me to spend time with ME.

I can not let that go. I am feeling that I don't matter. But he is doing this around the house to make up for those actions. I don't care what he does around the house at this point. I want to feel
that I as his significant other am number one. Yes he needs to care and tend to his daughter needs but he should not allow her to disrespect me. He tells her not to but does nothing when she does.

I am so close to moving on