You need to come back to her that you had no problem with her starting this and remind her that you encouraged it. Make sure that you are firm that she is the one that has caused this issue. She is the one that crossed the line from just friends to having an emotional affair and that she was even trying to meet him in person and possibly going into a physical affair. That you had no problem with her gaming and developing new friendships with both male and female. However, she is the one that caused this and ask her how she would feel if it was the other way around and how she would if wanted to still talk with a women that you admitted to having an EA with and was trying to meet with. Also, if you had admitted to having an EA with a woman and refused to let her see or have access to the communication to the AP what would she think?
I think this has to be cut off with no debate if you want your marriage to work. imo I wish you the best of luck!