AhoySailor.. I know there's no answers, but on some level it helps to know we're not the only ones. Thanks for replying. Much sympathy to you too.
What it seems to come down to, is that trying to do everything (have quality time with both parents, go to parties, go to clubs, keep up with both families, have trips/holidays) is difficult, as there are only so many hours in the day. If you think about, this is a problem that a lot of people have, regardless of child/parenting situations!
So this means, choices have to be made. The children, as much as we should be encouraging independent thinking/taking their opinions seriously, are not really old enough to make these decisions alone, as they are complicated and they cannot possibly understand the repercussions fully.
So the question come downs to how to make the decisions about what the children do. It seems in a lot of the situations being discussed here, the RP feels that it is their right to make all the decisions about what the child does, and that the NRP does not have the right to make these decisions.
In our situation, from what I've heard her say, I think this is because the Ex feels that as my DP doesn't do 50% of the parenting, she earns the right to make these decisions as she does the majority of the care. She also feels that as they live with her most of the time, their life is there, and that by taking them to stuff where we live, rather than where they live, we are creating two separate lives which is damaging. I think as the children are always living, wherever they are, they are able to make one continuous life for themselves, and that if both parents are enthusiastic about all parts of their lives, then they can achieve this!
It feels as though, until a court says DP has the right to decide what DSCs do when they're with him, we're up against a brick wall. If we had this reassurance that time would not be taken away, it would be very easy to support taking them to parties and clubs, as DP would be confident of knowing when he was seeing his kids. The issue comes when someone else makes those decisions and you just have to fit around them. So it does feel as though the only option is to stand your ground.. but as you say, doesn't get you very far a lot of time. But as DP said to me yesterday, all he has left is his integrity... so hold on to it.
Thank you for taking time to read and respond... it helps just to discuss it, to get my thoughts straight, so I can stay strong for my partner (and for me too!). It feels very selfish, just going into my situation in depth like this - so thank you for indulging me.