Thanks for replying and your time Harri.
It is frustrating as all get out. I am not sure how to keep out of the drama triangle other than to keep quiet and be careful of what you say and being sure not to validate the invalid especially given that you are in contact with all of them.
There are 3 sisters and the oldest lives very close to their mom. She has always defended her mom's abuse and drinking. The mother is High functioning and never abused the oldest sister's husband. The middle sister and husband eventually moved away after living in the same town for 2 years . We also moved away further to lesson our contact and for some job opportunities. We as husbands are both in NC with our MIL, oldest sister and her H. I get along well with one SIL and husband.
At one point the two sisters had a big fight with the oldest sister and mother when they defended their families.
Us going NC and with our wives and kids still being in full contact(most days) is causing underlying stress. We became the outsiders in this triangle with the MIL family unit. There are not much understanding or support for husbands in this dynamic. It was especially hard in the early days when the daughters sided with their mom or defended her behaviours. This dynamic is still happening to a lessor degree. There is always some drama going on.
I reduced the family stress by going NC, stopping/trying controlling and taking responsibility for other peoples behaviours. Stop being in competition with MIL and wive over children. Just going NC was a fight. It took a lot of work to get over the anger. I'm just working on self differentiation and boundaries now.
A while back I was considering going to a family event, but I found myself thinking how I'm going to defend myself or even getting them back. No, not a good idea and never went.
"being sure not to validate the invalid" This is a hard to catch at the time. Although I'm NC, I'll never really get away. Self differentiation seems the best option. I'm happy to say our house is calm at the and I'm working at keeping it that way.
How old are your children who are involved in the whole dynamic?
D7, D9. Oldest SIL - S17 and D20(with anxiety disorder), SIL - S6, S9.