Would it be pathetic if I anonymously informed my ex gfs fiancé that she’s a cheater?

Women do this sometimes among other women but never men. We would look pathetic and jealous at best and more likely creepy and stalkerish. This is almost unheard of when it comes to guys.

Anyway I am more angry at how my ex tried to cover up and self justify her bs by treating me as less than human then the actual cheating incident itself. I spent a very long time blaming myself for the relationship failing (I had my faults but never cheated). If she would of confessed it i would of been initially very pissed but I would of moved on much faster.
Updates
+1 y
Thanks for everybody’s feedback. I know I am not going to contact this guy. It’s more of a dark vindictive fantasy I had. Even if I did he probably wouldn’t believe me and she would do her best to cover it up if questioned.

This happened a very long time ago. She was able to harden her heart callously well back then. By now she probably has her self convinced it didn’t happen.

Anyway I did forgive her in a carefully written email a long time ago and wished her luck.
Updates
+1 y
I wrote it but knowing she had did this bullshit. However this new information has had a mixed impact on me. On one end I feel a sense of relief that I wasn’t completely at fault for things ending. On the other end it shows an insidious side to her that I absolutely didn’t know existed. I trusted her 100% at the time.
Would it be pathetic if I anonymously informed my ex gfs fiancé that she’s a cheater?
Post Opinion