Watching her dismiss his ED statement like she did is really disheartening. She didn't recognize any of the different behavior he's displaying. For someone who became so passive, he genuinely made the effort to initiate dialogue he is clearly uncomfortable with, then drops a bombshell on her, and she's like "oh he's just lying" and walks out? Really? She is totally locked into her view of things to the point she can't even see the cry for help for what it was.
At this point her cheating on him (with another married man) is pretty much assured. Here's hoping the husband finds out quickly and can get it over with already. My guess is she starts cheating on him and gets "happier" as a result, pretty much betraying the fact that something is going on, and then the truth comes out.
Neither of them are making an effort to truly understand one another. The sad thing is both of them really love each other. The second the idea of cheating comes up, the husband clearly shows his distress at the idea.
Kinda hope I'm wrong to be honest.