7-year itch. How many of us had things start to unravel at the 7 year mark? I bet a lot! Truth is, you can't take her back until she is ready to fully change and recognize what she's done to you. honestly, you don't want her back until that happens... The issue is not how to take her back but to delay the divorce. This^^ would possibly apply to them if they were to reach the piecing stage. Which is what he hopes for.
Being punitive, especially when it's premature, will keep them apart, imo.
You need to focus on you until she has proven (actions, not just words) that she is ready to really try and make things work.
That starts with intensive counseling with a good counselor; one that supports marriage and applies MWD's and Gottman's principles. He has no control over her. There are no words or actions from her to assess, except that she wants out. I feel as if we are reading too different threads.
Until then, you do you, man. setting boundaries will get you respect back faster than anything I know of. It gets worse before it gets better, but boundaries work.
25,
Not reading 2 different threads. See the part where I say "Until then." His focus needs to be on himself and the kids, also known as detaching. LiM said it best when he said that even though she may not be seeing this guy, she's still in the WW mindset; he knows what that looks like.