I will try to not make this too long, but also not drip feed. Please help me distinguish reasonable actions from my own emotions because, to put it simply, everything's at stake.
Been with DP for 4 years and, on the whole, it's a very loving relationship. He's good to me and my kids, fun to be around, reliable and helpful, contributes financially to my household. We don't live together but spend much (most) of the week at each other's homes (although more mine than his), as well as every weekend and holidays.
At the same time, it's been a turbulent relationship (I know that sounds odd after what I've just said, but it can be both good and turbulent, as it's about very defined areas of problems, i.e. one problem = his adult daughters). I have a good relationship with his youngest DD (early 20s) who lives with him, but his eldest (30) who lives away doesn't want to have anything to do with me. At times she's been really rude to me and various members of my family. Most recent example is a message she sent where she was incredibly rude and disrespectful (before blocking me, so I couldn't even respond - a coward's move, IMO). My DP did reprimand her, sort of, via text and heavily prompted by me, which I hate as I don't think it's my job to stand up for this relationship and my dignity, but his. I think left to his own devices he would just always avoid all conflict. He is very scared she will cut him out of his life.
I feel I've come to the end with being able to accept that he doesn't stand up for me of his own free will, and that when he sees her he doesn't feel a shred of annoyance, resentment or anger about the awful ways she's behaved. I understand we all love our children, and I understand he's scared of losing her. I'm not even saying that he should necessarily show her that he's upset about her bad behaviour, but simply that he should feel something for me, the way she's treated me (in other words, show ME - show some kind of outrage, empathy, solidarity). If someone mistreated my DP, even if it was my kids, I'd be pretty livid. I know people are different, and I know men and women can be very different in their emotional processing. But still. How can it be true that he loves me, but that he doesn't feel anything when someone repeatedly hurts me?
The other thing is that, when she comes to stay at his, although at all other times I'm (more than) welcome in his house, there's an expectation that I won't come while she's there. Now, I get that it's her former home, she still has a room there. But, at all other times, I have complete access to his house, not just that but he's even repeatedly hosted friends of mine for long weekends (because the house is big and has spare rooms and bathrooms), but when his daughter is there, the quiet understanding is that I'm not welcome. But, just as an example, we're spending Xmas at mine this year and he of course invited her too. I knew she would say no, but that's not the point. So, she's meant to be always welcome in my house, but I'm not only not welcome at family events, but also my own partner's house when she's there? It strikes me as very unfair and unreasonable.
I've been living with this for a while, and this morning I woke up and thought, I don't know if I love him any more. This has seriously eroded my feelings for him. It's a huge shame, as four years is a lot of time together and he's amazing in many ways and I love(d) him possibly more than any other man before him, including my ex husband. But this continued unfairness and indignity has eaten away at the core of our connection.
YABU - this is a reasonable compromise in a complicated family dynamic because parents will always put their children first, even when they're nearly 30, and most women would find a way to live with this, even if it hurts them
YANBU - this is a major breach of love and loyalty towards me on his side, and if he's not prepared to let her know that his home is always open to me, I should walk away even after 4 years together.
Can I just say (if you're read this far), if you're not divorced and in a relationship with a man who's got adult kids, you won't have any kind of realistic perspective on a situation of this kind. I'm looking for some thoughtful and considered responses based in first hand experience of these kinds of dynamics - thank you (and I'll disregard any responses that are rude or unkind, as often I see "pile ons" when it comes to these kinds of questions)