What would you do in my situation? Ex-wife's Fiance wants to talk.?

My first marriage, her 3rd. I was young dumb and naive, but treated her with respect, caring, paid for all her bills, never yelled at her and loved her and did everything I could possibly think of to save our marriage. Including getting her into a psychiatrist and medicated and into extensive marriage counseling. She treated me like a door mat and I seriously don't know whether I can marry anyone again she was verbally abusive, cruel, kicked me out of the house while I paid all her bills and lived alone in my paren'ts basement 1/2 the marriage. I learned her stories about her previous ex weren't all true from her own children and I feel embarrased that I ever fell for her and love her. Weve been divorced for 3 months and she's found a innocent victim of a 19 year marriage ending in divorce because she cheated on him. And he's walking around with his head cut-off so to speak (information coming from ex's bro. in-law) Now he is wanting to talk to me. However I don't get the opinion that he will talk to me without his Fiance present (my ex-wife of 2 years and one son). What would you do? I don't really want to get involved, but I just know that she put me through living hell and that there are so many similarities in the way she's caught and seduced this guy into her as she did me, there is just so many similarities it's scary. I don't want him to get another divorce, but I respect my ex-wife and don't want to harm her. What would I say? Is it even worth it? And Do I go out of my way or do I remain silent and let this older guy find out the hard way?