I should always be welcome in DP's home, regardless of who's there - AIBU?

It sounds like he hasn't stopped you coming over, but you both know it is likely she will leave. So you are not banned from the house you are just doing him the courtesy of staying away while dd around to facilitate him having a relationship with his dd. As long as it isnt too frequent I wouldnt mind.

I also wouldn't mind her being invited at Christmas but if she said yes i would expect this meant a new start and willingness to have at least a basic civil relationship. As she has said no then nothing to worry about, you get the Christmas you want.

If you don't actually want to live with him, what's the issue? Just don't cross paths with her. Let her have him when they agree to meet, you have the rest of him. You don't even want him for yourself full-time, why would you want him to restrict her access to him for when you're busy doing other things?

And yet there have been posts from people who have been in your situation who haven’t agreed with you, and others who haven’t but whose advice you’ve listened to.

Empathy and thought don’t always depend on having been in a situation, and don’t always magically appear even if someone has.

That’s entirely different though - OP would know what the problem was. In her own case she has no idea what she’s done to make DD dislike her.

So where do you and him see relationship going- do you intend to ever live together? Because surely this won’t work?

What would you do if one of your children had a massive fall out with him and be er wanted to see him again? It could happen. Would you force your child to accept that your partner can come whenever he wants regardless of how they feel?

If DD refuses to be around OP and is rude to her when she is, then l would think at the very least OP is entitled to know why. And if her partner is prepared to allow his DD to be rude to OP then l think OP needs to reconsider the relationship. DD may be important in her dad’s life but not to the extent where she’s allowed to be rude and disrespectful and to ruin his relationship with a long term partner. If OP is genuine and the situation is as she tells it, then yes, it is all about her, because she’s the one whose feelings come behind that of her partner and his daughter - not a position l would want or tolerate for myself.

You me ruined that your partner is conflict avoidant as if that's a flow but it's actually a quality.

It's a good thing to avoid conflict. In his eyes, he has a daughter and a partner he lives who don't like each other. He can't bake either like the other. What other option does he have? He either takes the side of one, and lose the other. Or try to give each what they need separately.

It's okay that he devotes some times to his daughter and it's inevitable that he doesn't give you much attention when he does because he can't give it to both at the same time.

If there's to be a winner, it's you since you share a family life with him AND her sister. Why do you want even more? You'll have your happy family for Christmas and she won't be with her dad and sister. Cut her some slack and enjoy the life you have.

The parent in this case wants OP and her kids to move in with him, to his DD’s childhood home and where she still has a room. Can’t see any measures that will work for that.

This shows a very small minded attitude which might contribute to why your partners daughter doesn’t like you.

There is more than one perspective that needs to be considered here. The daughter might have a valid reason to dislike you or she might not, but either way she is more important in his life than you are and she deserves her Dad to stick up for her too. You seem to think it’s all about you.

I find this comment strange. What has how her father chooses to spend his money got to do with her? I spend a lot of money on trips, clothing, experiences etc for my DH (second marriage) and it has nothing to do with my AC. My DH has 2 adult children, and like the OP, the one accepts me, messages me, is very happy that their dad is happy. The other rarely contacts their dad unless its to complain about what they haven't got or how bad their life is and never initiates contact but complains to their sibling that they never hear from Dad!! I stay out of it as much as I can and fortunately they live abroad so don't see them much. The only thing I have said is that if the one who, for some reason doesnt like their dad being happy, keeps upsetting him with some of the messages sent then I will message them. I am the one who deals with the fallout which has happened several times in the last 5 years we have been together. He defends them but knows deep down that its a one sided relationship but cant stop trying even though he gets upset. Its ok saying "kids come first" which is true when they are young but these are grown arse adults who have their own lives and probably don't give dad a second thought most of the time. Whilst I have never asked my DH to choose between me and his one child if they continued to be rude to me and he didnt sort it then we would have a problem. As I've said, in my situation I have been honest with my DH about his eldest child and the way they treat him, how I find it distasteful and how, if it affects us ongoing then I will have to say something myself. Not sure OP where you can go with this but if he is always going to allow his daughter to be rude to you then I think you deserve better, imo.

An adult child has no requirement to have any positive feelings about the partner her parent is with, nor any need for your paths ever to cross.

The parent is entitled, presumably knowing this, to put measures in place so that your paths do not cross.

because to me it seems like she does have something I want (his backing).

I don’t think you should want that. Don’t be the reason that he and his DD fall out or don’t see each other. That would be the end of the relationship if you do.

I’m not divorced, but my parents are. It took me a long time to accept my father’s wife. I didn’t like her and she’s still not my cup of tea but here we are.

You are not his wife, you are just a girlfriend in her eyes. And if she wants to go and stay with her dad and her sister without you around then fair enough. She should be able to do that, even if you were on good terms. There’s nothing worse than parents foisting their partners on their kids. She wants quality time with her family, not you and your family.

Not being able to drop in over the infrequent weekends she is visiting seems a strange hill to die on. Also, you suggesting that he should lunch with her in a restaurant and not his home makes you sound like the controlling one, not her.

If I were you, I would keep the door open as you have been but otherwise just not give her any headspace at all. She’ll either come round eventually or decisions will need to be made and discussed as and when you move in together. But for as long as none of you live with each other, it doesn’t really matter.

How happy would you be if you made plans with your partner and his DD turned up unannounced and expected him to cancel his plans with you in favour of spending time with her ? On repeat ?

Can I ask what you would like his response/ reaction to all of this to be?
Would you like him to still be inviting you for dinner on the times that she is visiting?
Why don't you like the reaction that she would leave if you were to come round- isn't that probably the best way for it?

And I can't remember if you said how often she visits, sorry, but say it's a week every 3 months. If the situation was reversed, and that's how often you saw your DP, 4 times a year, due to him being with/ available to his kids and you not being a part of his life in person for that period, would you be accepting to not having his attention during that time? I appreciate this is of her doing, as she has decided not to be around you, but just to reverse the situation.

I also don't think you can treat this the same as if you were living together, as you have decided to live apart for now, partly because you would like your own space/ time- surely this comes under that?

I was referring to the Framingham Heart study data:

pubmed.ncbi.nlm.nih.gov/24748689/

This is a great article that has a link to the original study and also explains some of the findings I mentioned:

’McDermott and her colleagues found that study participants were 75% more likely to become divorced if a friend is divorced and 33% more likely to end their marriage if a friend of a friend is divorced.’

www.pewresearch.org/short-reads/2013/10/21/is-divorce-contagious/

TBH she sounds a bit spoiled and entitled. She's not 5 years old ffs, she is a grown adult and needs to start behaving like one.
I do hate all this bullshit that parents must always put their children before anyone else, at all costs, regardless of how they choose to behave! Unless there's a huge back story, being In her 30s she should be mature and adult enough to accept that you are her dad's partner. She doesn't have to like you, she just needs to be civil. Life isn't fair. It never goes the way we all hoped/planned but we just need to get on with it.
How would she like it if her partner/husband wasnt welcome in her dad's house or yours for that matter?
I do feel though that maybe you should respect her time with her father by not going round unless absolutely necessary though as you're just asking for conflict if she's that immature. Why bother poking the bear??
This is (as always) a DP problem as he is the one enabling this behaviour to continue.
And before anyone jumps down my throat, yes I am part of a blended family so I do understand the dynamics of such situations.