Gala Girl, that is all really practical advice. In particular, you've repeated something I already knew-- I need to take ownership of my own choices and needs. I've been trying to do a better job of expressing throughout this what exactly my needs are.
Yes, a lot of this comes down to my partner not really serving as a great bridge between me and my meta. He's helped contribute to our system where I have to ask for indirect permission for many things in our relationship. We're working on that. Following this new drama, I finally came out and told him that as much as practical, I would like to be an equal. I know this can't mean 50/50 time in our situation and that's fine. I also have a busy life. But, i told him, if he wouldn't ask for my approval before meeting her for an unscheduled lunch, there is no reason it has to be that way for me. It's more a matter of principle, and it's little things like that that would help me.
I do want to point out that before the pregnancy happened, we had all had our ups and downs, but for several months things were pretty good. Just this past weekend, the four of us (me, D, S, and S's partner) had gotten together for a family BBQ and had a great time. Generally there weren't a lot of immediate issues other than the communication/scheduling principles I mentioned above. Which is why it did hurt so much to find out they had planned this huge change for all of our lives.
Magdyln, thank you as well. I really think I needed to hear that from someone in the community. I wasn't sure if my feelings were justified about this at all. It's not really the physical thing (sex, I mean). As far as I knew they very rarely had sex and we are all fluid bonded anyway. And the time span between trying and success was, well, 2 sessions. They had expected this to take many moths though, and I assume they were planning to wait the many months before telling me.