Stuck in the middle

So I just got off the phone with my brother. And for the millionth time in the past 10-12 years or so, I feel like I'm stuck in the middle. Quick backstory, and I'll try not to go into too much detail b/c its a long and complicated situation and I know you don't want to be reading all day. Basically, my brother and his wife have gone through at least three periods of not speaking with my parents and my sister and her husband. At some point its been at least partly the fault of each of the 6 people involved. Its practically impossible to determine why exactly things fell apart between them all originally or even why they seem to now have greatly improved. To sort of sum it up, at its worst, I used to have to make separate plans of my own to visit my brother's family at holidays...even though they live only 10 minutes from my parents, they wouldn't speak to each other let alone be in the same room. I even had to take pictures of my youngest nephew and e-mail them to my mother so that she could see her grandchild for the first time. It just has been a bad situation. And somehow through it all, I have been like Switzerland...the neutral party. Which is good, in that, I have never had to be without any member of my family in my life...but hard in that, both sides of the situation feel like I am a safe person to vent to about the other side. Now, for the past 2 years or so, everyone has been getting along pretty well. Really well, actually. And I have been thrilled. We can have entire family get-togethers. I haven't had to hear any complaints (or at least not many) from one side about the other side. I have been hopeful that maybe, just maybe, we could put all the fighting, not speaking, and tension behind us and be oh, I don't know, a regular family? And now we get to today. This weekend we are having our family Christmas. I have been SO excited about this because last year we didn't get the entire family together for Christmas (no bad reason, schedules just didn't work out), and I am just so looking forward to everybody being together, giving gifts, enjoying the Christmas spirit and enjoying time together. But tonight, my brother calls me to find out when we are driving up there. Apparently my mom won't "schedule" anything b/c they don't know when we are coming (doesn't matter that I told them we'd be there by lunch on Saturday at the latest). So I explained to him when we'd likely be there and we could probably do the "official" get together in the early afternoon. I probably sounded a little frustrated, due to the whole getting a guilt trip on not spending enough time up there from my parents (balancing family and the farm...a story for a whole other post). Well, that let loose the 'vents' from my brother. How mom never feeds them when they're over there (in her defense, J, my brother's oldest is the pickiest eater known to man...in my brother's defense though, why would your mother not offer you any food when you're there at dinnertime?). How my brother's wife even brought a loaf of some sort of quickbread over last time, and mom promptly put it in the kitchen and didn't open it. (what? that is sort of weird I have to admit). How every year at Christmas, my sister's boys open all their presents from our parents before my brother's family even gets there. How he knows, and he's afraid that soon J will figure it out too, that its because mom and dad get my sister's boys more stuff than they get my brother's boys. And unfortunately, this is probably true...they have a tendency to favor my sister's boys...but in their defense, my sister and her boys have been consistent in my parents lives...my brother and his family has not. However, now that my brother is "back in the picture"...favoritism between the grandkids should not be happening. But here's my thing. This is where I'm "stuck in the middle". I know all this now. I know my brother is obviously frustrated by all of this. I see his point, I understand his frustration. And now I worry. I worry that this is the beginning of the end. That something is going to snap in the delicate threads that are holding the family together. I want to make my parents realize that they are still acting like their son and their daughters are different....like they favor us over him...that my brother is not stupid and he sees this, that my nephew is not stupid and he is going to see it soon enough, that walking on eggshells around them, even after 2 years of getting along, is not HELPING ANYTHING. If anything, it is making things harder...its reminding everyone that no, things aren't quite "right"...we are all still terrified that everything is going to fall apart, and in my opinion, makes things even more likely to fall apart. They need to treat us all equally, forgive past "sins", let the past GO. But here's where it gets even stickier. I can't tell anyone in my family any of this. I can't tell my parents any of those things, I can't even tell my sister and try to get her help in maybe hinting or somehow getting my parents to realize they need to be more "equal". My sister holds grudges and will take any chance she gets to criticize my brother, so I can't talk to her. My dad is stubborn (like my sister) and I think he still has a sort of "wall" up when it comes to my brother. And my mom is stressed because of Christmas and easily upset...so bringing it up to her would definitely only make things worse. So now I feel like I am stuck with this information. I am so afraid that these are the beginnings of the "straw that broke the camel's back" and feel like I should DO something to fix/prevent it. But what? And how? And maybe my brother was just venting and I should just not worry about it. Maybe its no big deal. I am sure the pregnancy hormones are not helping in this situation. I just feel stuck. Like I know something bad could be coming...but I can't prevent it, b/c if I try to, I might just make things worse. Stuck in the middle. Again. Because I didn't have enough weighing on my mind and my heart this week. Tomorrow is the due date of our first baby. Again, a topic for a whole other post. And this one is long enough. If you've read this long, thanks. I guess all I'm asking for prayers that my family can stick together...and maybe advice, if anybody has it. Because I'm just stuck on this one. :(