My heart is in her hands

[SDFoundGirl]

If you're going to respond to your W, then do it in a conversation, not in a letter. You can walk away from a conversation if she begins to escalate.

I'd say something like this:

"W, I'd love to explore dating with an eye on rebuilding our marriage. However, I won't live in an open marriage. When you are willing to break off contact with OM and agree to a transparency plan, I am willing to move forward. Until then, I'm afraid I can't agree to dating."

Or something like that. It gives her an option, it's not pursuing, it still allows you to show your 180s and being the better option, and it demonstrates respect for both her and you.

SD