Might you consider setting a boundary on this NDY? Letting her know that you regret the recent discussion was seen by him and he was upset. Letting her know that you don't intend having any further such discussions if he is present. And if she begins one, calmly tell her - we can continue this discussion at another time when we are alone.
Hi Toots
I did. this happened a few weeks ago (different subject this time) and I did try to talk to her. Because she didn't listen I sent an email instead and she agreed and apologized.
Remember the events of yesterday. One, the discussion on the house and 2, me interrupting her txt to the OM. It was fairly obvious what was going to happen, The boundaries are set. But like I said earlier I need to work on getting out of her way.
Me:43 Her:42 M:14 S:9 EA started 2014/03 (or there abouts) PA started 2014/05/30 BD:2014/11/05 I left 2015/10/01 I returned 2015/05/02 She left 2015/06/10 OM still on the go.