Results: How do you really feel? / How well do you think you know your friends?

I used to work with a gal, we became friends, talked to each other on the phone, went to work events with each other, visited each others' houses, I babysat her kids, etc This went on for at least 3 years. Once I had my daughter we spent even more time with each other (she had 2 kids at time that were also young). We had a mutual 3rd friend and I started to notice that they did things together but I was never invited .. shopping, karaoke, dinners, etc. I finally asked her, why are you and E always doing things together, but I am not invited or you and I don't do those events together. She told me that I was only a friend to her for her to tell her affair details to. (Oh ya, the entire time she was having an affair). She went on to say, you are the only one who doesn't know my husband, family, in laws or neighbors. So I feel comfortable telling you about the affair, but I don't want to involve you in any other area of my life. Once she told me that I stopped returning her phone calls; basically I was just a sounding board. Have you ever been in this situation, where basically you were just a "tool" in someone's life to use when it was convenient?

Unfortunately, I ran into this gal so many times at university, but managed to avoid any long conversations. Would you have talked to her?

I never did tell anyone that she was having an affair; I look back and regret that I didn't, as I feel she might've been neglecting her kids. She is still married, don't know about the affair part. Would you have told her husband?

Have you ever treated someone like this, just had them in your life to tell discrete information to, and wanted them for nothing else?

If she would've been more honest about her so-called friend intentions with me, do you think that what she did would've been considered ok?