When do we tell the kids?

OK, I'm looking for some advice here.

Last night I asked Wife, "So what do we do now?" It was the first time we had talked about our marriage since we met with Counselor two weeks ago, and we meandered around the subject in a slow, desultory kind of way. We confirmed with each other, as if there could possibly be any doubt, that splitting up is all that makes any sense. At one point, for example, Wife said that she didn't want to live under the same roof with somebody who openly scorned her; I agreed that I don't want to live with such a person either. And I don't think either of us admires the other very far these days. At another point Wife insisted that I have been pointlessly cruel to her over the years, which I can account for only by thinking we must have very different definitions of "pointlessly cruel" ... different enough to constitute (so to speak) different languages. Nor do we have a common moral compass any more, at least not when it comes to claims against her medical insurance that I think count as fraudulent and she doesn't. (There are probably less self-serving examples that indict me instead of her, but -- predictably enough -- I can't think of them right now.)

But one thing I wanted to insist on is that we not drag the boys into this discussion yet. What I really wanted to avoid is that Wife start messing with their heads, like she did with Son 2 in this post. But I don't know how to say that or spell it out, so I opted for a broader blanket request that we just not talk to them.

It looks, however, like I was probably wrong. Or at least I hear that from two sides already.

The first is D, who wrote me an e-mail this morning that said, in part, "If you think the boys don't know that you are preparing to divorce Wife, you are engaging in wishful thinking. They most certainly know, both because children, particularly children as bright and sensitive as yours, make it their business to carefully monitor their parent's relationship and second, because she has undoubtedly said a great deal already, which is why she hesitated to to keep your discussions a secret. I'm all for transparency. I see no value on any front to keep this a secret. Children need to understand that people work together and forge a path through difficult matters by discussion and compromise (why does everything need to be settled before you say anything?), and they need to comprehend the fundamentals; that both parents love them and will be a part of their lives in the months and years ahead. They also should have the opportunity to ask questions and express their feelings.The idea that you 'know' what concerns them is almost certainly untrue, and you would be wise to address their worries directly. They also need the support of their wider community; the school should know, their coaches should be informed, and your parents need to be in the loop. We need each other during difficult times; secrecy serves no one well." Then later today I was thumbing through Judith Wallerstein's What About the Kids? and ran across a paragraph that says, "If your children are old enough to attend school, you should gently run each [suggested parenting] plan by them. Tell them that you had a meeting, these are some of the plans you have in mind, and do they have anything to add? Did you overlook anything important to them? ... But make it clear that they have a voice, not a veto."

So my plan was probably wrong.

But then what is right? At what point do we tell them, and how do we say it? I don't want to get this wrong -- heaven knows, at this point doing the right thing for them is the only reason I have for moving slowly and gingerly. (Fine, maybe not the only reason. But a big one.) But I don't know how they will react, and I don't have any clue how to proceed or approach it.

Advice would be welcome.