Hmmm.
Keeping score is not really a good thing, but this raises a question in my mind. Is it possible that the other wife was not all that interested in having sex with you anymore? Not that you're not an absolute stud but these things do happen. After a relatively long period of an exclusive relationship, she may have wanted to branch out.
I don't think anyone has said this in this thread either, but after thinking about this and trying to put myself in your place, it occurred to me that part of your irritation with your friends is that you feel rejected. Nothing unreasonable about feeling that way, considering that they dropped you.
You had an exclusive relationship with them and then they just dropped you, avoided your attempts at making plans and didn't respond to your efforts to contact them. In my opinion, if they respected you, they would have at least said something about wanting things to change. So on top of feeling rejected, you feel disregarded. Well, it seems to me like you are perfectly reasonable if this is the case. Actions speak more loudly than words. They might be cool in public but they have acted poorly toward you in ways that are important. The husband not responding to you after what happened, is another sign of disrespect in my opinion.
Here's another thought: you said your wife and you feel differently about the state of your friendship with them. I don't mean to be bringing up the worst things all the time, and I apologize in advance, but: is it possible that she does have a different friendship with them than you do? One that she may not mention to you? Sometimes if it walks like a duck, quacks like a duck, looks like a duck... you already said that even when the four of you were "on", that you were most often the one who sat out a threesome.
I would be really interested to hear what your wife has to say after the two of you talk about how you feel about what happened, and any new rules you may have for her in the future about this couple. I don't think you've said much about how she feels except that she still thinks they are friends.