<human>: Can you provide a brief rundown of the text in within 3 sentences?

So I dated my ex 19 female for about a year. While dating I found out she cheated on me, I tried to make the relationship work but It just wasn't happening. Well, come to find out, she also cheated on her ex bf of two years multiple times. A lottt of times actually. But the guy never found out and she still hasn't told him to this day but she did tell him she cheated on me. Weird right :/. Anyway fast forward to now. 

I don't talk to her at all. We haven't spoken in about 2 months because she tried to reach out and rekindle things with me but I declined. However, one my friends found out she is talking to her ex again. I told him to not tell me information like this I don't care to hear it. But since then it's been kind of bugging me. When her and I dated she said she never loved the guy at all and she used to talk to all sorts of guys behind his back. The reason she broke up with him was because she wanted to push him away. Because she didn't love him. So he was basically forced out of the relationship. Now, she's trying to talk to him again.. My friend could have bad sources and maybe they're just trying to be friends? (probably not the case with her she loves playing people.)

But my question is, should I tell her ex about what she's done? Because believe me, unless you find out yourself this girl will never tell something she's lying about and if they do end up dating the cheating will occur over and over. OR should I just let life happen and put this in the back of my mind?
<bot>: should I tell my exes ex that she is playing him now and also played him in the past? Or should I just let life happen and ignore it?