My apologies, I thought you posted earlier she had lied when it was actually people who had mistreated her.I am on excellent friendly terms with all 4 of my married EX's and normally we chat emails...
Having said that, I must state it is very odd to me that someone is on friendly terms w/ all 4 of their ex's who are now married. I can only hypothesize that you are a genuinely good person who doesn't want to hurt anyone's feelings but ultimately suffers from "nice guy syndrome." It looks like you were Mr. Rebound before they went on to marry some schluck who they now want to vent to you about at times it's convenient for them because they know you'll always be that NICE guy that is there. It's as if they are making you into one of their GF's to bounce stuff off of to get a guy's perspective.
I'll say this as well. If you ever get married and/or have a serious GF relationship they won't allow you to keep in touch with all your ex's. My wife would not allow me (not that I would want to) and I would not allow her. MOVE ON my man!