Why bother with all that? If you know she is lying to you all the time and you don't like it, why bother staying with her for more of the same? Wow, even if I loved her I personally would not stay in that situation, I don't know why she would stay with you if she is lying to you so much and seeing other people, what does she get out of it other than self guilt and feelings of low self worth or power over you?

You need to have it out with her once and for all, if the end result of that is not satisfactory then, if it were me I would walk. But I would have walked after the first 2nd chance was broken anyway. Good luck with that