[UPDATE]: Should I (33F) tell my ex’s (28M) girlfriend that he pathetically contacted me?

Link to original post: https://www.reddit.com/r/relationshi...riend_that_he/
Original post TL;DR - Dumped ex for cheating. His other unsuspecting girl reached out to me to tell me the details and saved me from further heartache. They’re now together and he has contacted me in an attempt to get me back. I’m not interested, but should I tell her?
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Update: Sorry for the delayed update for anyone that was interested, but I moved and life has been hectic. I read every comment on the original post and considered every option. A couple weeks after my ex initially contacted me via email, he sent me a text message asking if I would ever talk to him again. Like before, I didn't respond. A couple days after I moved, I messaged his gf/the previous "other woman" on Facebook since that was my only form of contact with her. I first asked if they were together, to which she responded "yes" a couple days later. In a brief conversation I told her that I felt I owed her the courtesy since she once extended the same to me. I told her he had contacted me twice in the last month and gave her the gist of his email. She said she figured that's why I was contacting her, said she really appreciated me telling her, thanked me, and said she hoped I was doing well. I told her good luck and went on my merry way. No catfighting, no unnecessary chatting.
In the end, I feel bad for her. Yeah, she made the horrible decision to get back with him but I'm sure she did hoping/thinking he had changed. He never will. Men like that don't. I was his unwitting fool for nearly 5 years, now she has that burden. I haven't heard from him since or heard anything from his family who still occasionally keep in touch as to whether she dumped him or not...my gut instinct is she didn't. Either way, my conscience is clear, a "favor" has been returned, and I'm still happily no longer with a cheater. Cheers folks!
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TL;DR - Contacted the gf, told her everything, she said thanks, we went our separate ways. No Jerry Springer.


Source.

Just going by the title, I say yes tell her.