Why is my wife protecting the affair partner?

To start I had an affair. Then I found out that when I had mine she went and had one. Where I came clean about all and everything she still has not. She does not want to discuss it with me. I don't understand why my wife is defensive or protective of her affair partner and his family. She seems to put them and what would happen to them over us and me.

I also know she has talked with two of her female friends and one guy friend that is older and told them about her affair and mine. She wont even admit she told them when I said something after one of the women and the guy at different times slipped up about it and let info out. I just do not understand why she wont talk to me and tell me the truth when I tell her what I know about her affair and the little I know they know.

Any advice to help my racing mind