I was apologizing because had I known for sure that my W would be doing this, I would have stayed home and not put the burden on her parents. I only asked her what she planned on doing with the kids (what activities, etc.) this weekend and she simply said that she doesn't know yet. At that point, I didn't think it would have been beneficial for me to probe her further and ask if OM was coming and if she planned to spend the weekend with him.
We are living our lives separately, but we are parenting together when we are in the house. It's not an open marriage in a sense, because she is not committed to me in any way. If I were to push the issue, she would simply say, "fine, I'll move out" or "fine, I'll file for D". It was she who on several occasions have told me that living together is not a good idea given that we're "unofficially separated".
If you have any advice on specific boundaries I could put in place, I'm all ears.
M: 15 years BD: 6/25/14 EA/PA: starts 5/14/14 11/30/14 - A ends 5/15/15 - D is finalized. 11/28/15 - Start of new LTR with a wonderful woman (and still going strong)!