It played a role in the MR. My parents spent less time visiting, because they didn't feel welcomed by my W. Plus my W would make little slick comments on occasion. And my father doesn't play that. So he would say something back. And she would play victim. I spent quite a bit of time playing peacemaker. But W had no problem having her family coming to constantly visit and us trying to get them set up in this city for better job opportunities. And my parents have actually helped us out on a occasion.
My W got into with my SIL, which resulted in my brother and I not speaking from 2/15 until 12/16. Not because we were mad at each, but because we took the side of our wives. All because my W ran her damn mouth. So my parents were pissed about that as well. But I stood by my W and defended. And while doing so, she is out there cheating.
Nobody is asking for them to take sides. But don't act like I don't exist either. My brother and his W were separated for over a year. My family didn't pretend she never existed. They stayed in contact, even asked if she needed anything. So when they got back together there were really no hard feelings. My W family have treated me as if I was the one out sleeping around with someone else's spouse. So if a R was to happen. Things will not go back to the way they were between me and them.
Well, this looks like something maybe you can work on. instead of blocking out future in laws, how about you examine why you took sides and didn't speak, rather than agree that there is beef between the two of them, and you and your brother should maintain the integrity of your R.
You play the blame game a lot. You blame your W for a lot of your external problems/R's. A great learning experience is how you could have handled things differently to maybe change the outcome for yourself a little.
Your W's cheating isn't your fault. But you need to really look inward. This is the best opportunity you'll ever have to do so. Many don't get that opportunity. I am so grateful for the chance to look at ME and see how I could change the outcome and situations without just reacting to what's going on around me.