And the thing is, remaining detached is essential for life. When we begin relying on someone else for our happiness and being less than authentic because we're concerned about their reaction, that's always poison for a marriage. It comes out in different ways.
Pre-bomb, my H could never "hear" me when I tried to bring up issues, so I stopped trying and it came out passive aggressively. Now that we're 4 years past bomb (and three years reconciled), I'm still detached. When I have a problem, I bring it up, and I detach from the outcome. His reaction is his business; my behavior and needs are my business. Because he always has a choice and now I understand that, H responds better to the way I put things to him. It's been good for our M.
As a woman, I agree with the gentlemen here. You don't need to be a jerk, but you do need to be a man. Men have boundaries. Men don't roll over and submit to whatever the woman wants. It's why I lost respect and attraction for my H. Know what got it back for him? He bombed me. Was in an EA. I never expected that from him. I sort of believed he was the type of guy who would take anything I had to dish out and he'd always be there. He got my attention when he called BS.
Now, H wasn't blameless either, but this is my side of things. Your W has things pretty cushy right now. She gets to explore all the fun stuff with the stability of a nice home and income. Even with support, she's going to have to get a job when you D. Your S will be split between two houses. She'll have to pay for her own stuff. She's totally cake eating, but she's wrapping it all up in, "This is what's best for our S," thus making you look like a jerk if you call her on it.
But your W isn't concerned about your S if she's thinking about screwing another guy or engaging in an affair while she's still married. It's just a convenient excuse to cake eat. A smokescreen.
Be prepared for your W to lob horrible words at you when you put your foot down. What you have to always ask yourself is, "Is that really true?" Don't react. Respond with, "I'm sorry you feel that way," or, "I can see how you might view it that way." Don't defend, don't argue; get clear about what's acceptable for you, set that boundary, and hold the line.
SD
Me: 40 H: 43 H had EA from 2/06-9/06 Bomb 5/06 Piecing since 9/2006 3/2008: Boundary setting 7/2009: Boundary crossing~dropped my own bomb. 8/2010: Marriage finally on track!