Wow, sounds like a page out of my book! It's hard to say where the fault lines are in this and what you (and your bf and his wife) can do to make things better. A two-person relationship is infinitely complex and can't be summed up in a library shelf full of books. A triad or quad relationship makes it that much more dynamic.
I know in my relationship we work extremely hard to communicate everything. Sometimes it causes fights that probably could have been avoided. When our girlfriend left us, she had stopped communicated with us for several weeks. Her disapproving friends convinced her we weren't right for her and she finally bought in.
Earlier on in the relationship we had a couple breakups because of what you were describing. I believe everyone has to give it 100% or it won't work. And should it not, or should someone else not want to give it 100% then I've learned you can't hold yourself at fault for that.
If you feel like you're giving 100% and it's not enough then I'd venture to say that this may be a dead end for you. You should never feel like you're giving it your all and there's always room for improvement. If your situation does not encourage you to be a better part and person then most likely the others involved aren't aiming for 100%. If this is the case, don't let it get you down. It takes two to tango... three to drive in the carpool lane
(I guess that means you're going nowhere if the three/four people can't be in the same car together)
Nevertheless, good luck. Keep us updated! And I apologize if I didn't give you the hope I'm sure you were looking for. Given enough time, things have a way of working themselves out for the better or worse.