I think the thing to remember when things like this come up are that our WS are WS because they often lack the foresight to see their actions to the logical conclusion.
Also the WS rarely has a lot of "emotional intelligence," until they work on that growth.
If you lose your leg in a car accident due to the WS driving does it make your lives easier if they chop of their leg. At least we are the "same."
If you are both cheaters then it follows that you belong together, right ?
My W too offered me a hall pass after Dday. She somehow thought it would help my feelings of being a doormat, chump, etc.
The only request was that it not be with someone she knew and did not tell me about it. My response was very simple, " I would know. My integrity is one of the few things I have left. Do you want to me to lose that too?"
She cried pretty hard after that. I think it helped add a little understanding to why I was so hurt.
Discuss it with her. Ask her why she thinks that it would help your R. Or was it a desperate attempt from a broken person.
It will help you understand where her head is at right now. If she cared about you she wouldn't be suggesting this. She knows what burden she has to carry. Why would she want that for you on top of the burden you carry from her choices ?
Don't get me wrong I see how someone without a healthier mind would think this would be OK.
However it ends and begins with she did not have hall pass when she cheated did she ? Now she expects you live with the consequences. What else can she offer you that achieves the same result.
She thinks giving permission is her doing the work. It really is not. If you wanted to you could have an A without checking with her, right ? She needs to work on herself and be safe. Turning you into an unsafe partner is not the same thing.