DB is about doing things that work. Is anything you have been doing working? Nope. Confronting someone and setting boundaries are important things. Of course she is going to be mad. When a child gets caught doing something they know they are not supposed to be doing and are called on it, who do they get mad at? Themselves for doing something wrong? Nope, the parent for busting them. Same situation! You are calling her out on things she knows better than to do. Justifying it by saying, "We are just friends?" is an excuse to make them feel better for doing something wrong. They feel guilty and lash out. It is script. Ler her know you know. Let her know you don't approve. Let her know your boundaries. You simply say, "I will not be in a relationship with someone who is having an emotional affair with someone." You don't tell her what she needs to do. You let her know your boundaries and she can make choices from there.
What is so good about being in a relationship with someone who has someone else? Why let it go on? Do you believe that counseling will be effective if she is still having the other relationship?
"It is excruciating pain. It is the pain of separation, the pain of loss, the pain of dreams and expectations unrealized. It is the loss and death of a mirage."
