This isn't solely about placing blame on any one. It's a matter of finding out what happened before and seeing if it may have been the cause for his current sitch. If the original problem isn't taken care of, even if his W stays, there's a posibility that the problem is going to resurface.
Let's face it. Some of the D who have been "busted" end up back here because the couples either didn't nurture their renewed R or didn't take care of the original problems that caused them to be here in the first place. You see it time and time again.
Having an A is one of the most selfish things that an individual could do and there's never a reason why someone should do that. He had one for a month and kept it hidden.
It may be one of the main reasons why she's leaving or maybe not. But he should look at all alternatives to see how best to communicate with her.
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.