Having to ask, for me, is a non-starter. Who can live with that kind of anxiety. Having her offer the information to you relieves you of having to wonder, and that's what provides comfort and the ability to work on trust.
I would play hardball with your boundaries Breakdown, stake out your territory and show her you mean it. To Mach1's point you're not trying to control her, you're saying that to be in a relationship with you, this is what you need to have and how you need to be treated.
If she thinks that's unreasonable or not doable, she doesn't have to be in a relationship with you and you can put the divorce back on the table. I think she'll be more willing to negotiate than you might expect given where she is, but once she's back in the fold it gets more difficult, so now is the time to figure out what is non-negotiable and stick with it like your life depends on it! (And of course it has to be bi-lateral).
There is good information on Pat Love's web site for where you are. Go to the "Downloads" section and start with the Office Spouse survey -- that gives you a template for being very specific about what is okay with you and not okay with you in terms of friends of the opposite sex. You should both agree on it and mutually agree to disclose if and when either of you are tempted.
Accuray
Married 18, Together 20, Now Divorced M: 48, W: 50, D: 18, S: 16, D: 12 Bomb Dropped (EA, D): 7/13/11 Start Reconcile: 8/15/11 Bomb Dropped (EA, D): 5/1/2014 (Divorced) In a New Relationship: 3/2015