Why did she tell me?

This girl is out of control. Of my circle of friend she's slept with atleast 3 of the five guys in the group. It has been alluded to that she has made it with another friend who is married. His wife is my friend as well. I was once very close with the girls in question. However, over the last couple of years I've really gotten to know her and she isn't such a nice person. She lies at athe drop of a hat to EVERYONE, even her family. She recently confided in me about her relationship with the married friend I mentioned above. I've asked her not to discuss this any further as I am friends with all parties involved. I feel really guilty everytime I talk to my firend. Especially when she vents about having marital problems.................
Category Didn't Want To Know - But I Do