No don't discuss it with them, they will absolutely side with her no matter how strong you think your relationship with them is. "Blood is thicker than water" absolutely applies. Many LBS's have thought they had helpful in-laws only to get blind-sided later. It's fine to remain friendly with them, but no R talk. If they bring it up then just say the two of you are taking some time to sort things out and leave it at that. ...
I absolutely understand that they will side with her, and my relationship isn't that strong with in-laws. My thinking was to clarify our situation in that I did not choose for WW to move out, and that I'm standing for the MR and not abandoning it. I guess not filing for D would already indicate that from my end. I would have to intentionally reach out to talk to them, otherwise there's no chance of me interacting with them.
