I have two reactions to this thread.
First, from the standpoint of your situation with your girlfriend, it is very difficult for anyone to say "Get Out" if they are not standing in your shoes. Unboubtedly, you are very torn, and tormented about this issue if you are bringing it to light in this public forum, as you seem to be riding a rollercoaster of emotions about what to do with your girlfriend.
When my parents were having marital troubles, my mom once left a therapist's office who kept pressuring her to "get out". Although my mom knew my father's severe emotional difficulties, she didnt like the idea of being pushed into divorce when seeking help. Sometimes, get out, is not what one needs to hear.
That having been said, if you are experiencing a situation where your girlfriend is blatantly lying to you about such important issues as talking to her ex boyfriend, and other serious issues, issues she knows are serious ones, how can one stay in a relationship which is supposed to be based on love, and trust, with a person who is lying to them, and not being truthful? If you cant trust your girlfriend, who can you trust? It would seem to me that although this might be a very painful step, if you cant work through this serious issue with her, as much as I hate to see breakups of relationships, it seems to me that you cannot stay with someone who is a liar, and who you cannot trust.
As a sidebar: Mimis, and Iam not saying this to sound like suck up to a mod or anything, this is a person to person comment coming from the heart. I think it was very brave, and showed an incredible degree of courage, to share your personal experience of contemplating suicide and treatment on here. Depression and suicidial thoughts is an extremely personal and challenging situation. I was in therapy for years, and often comteplated suicide, due to the brutality, that you are aware of, that I suffered at the hands of my father, emotionally. I have overcome, and while I still get down, I know that nothing, not even an estrangement from my father, is worth taking my own life over. Heck, when my parents were married, my mom, who I thought was the most stable person in the world, used to talk to me of at times driving her car in front of a train, due to the emotional abuse, and lies, she suffered from him, but didnt, due to the fact that she didnt want to leave me with him, and she loved me too much to do that.
I hope Iam not getting off track here, Mimi's post got me thinking. Back to the issue at hand: As to the issue of your girlfriend, Iam always in favor of attempting to work relationships out, because I dont like breakups, divorces, or estrangements. I will say that the issue of lying and non trust is a very serious one. I think you need to make your feelings known, and if it bothers you that much that she is talking to her ex, and especially lying to you about it, which is a betrayal on two fronts, you need to insist she stop, or it may be time to move on. As for the issue of how you said she comtemplated suicide when you last threatened to break up with her. One never wants to drive another person to despair, and you want to be human to others, however, this doesnt mean that you should sacricfice yourself, continue to be with someone you cant trust, and put up with her lies and deceit due to this. This issue needs to be worked through, somehow, or else, it may be time to move on.
I hope what I said helped. Whatever my shortcomings as a person, honesty, trust, and loyalty is the most important trait in a person to me, and one I pride myself on. It is the issue that led to what will probably be a life estrangement for my father and me. If you dont have trust, you dont have anything. This issue needs to be worked through now, or, as painful as it may be, I feel that one needs to think long and hard about staying with a person you dont trust, as painful as that decision is, is it worse to stay, and perhaps be hurt more in the long run?
Mitch