Sweet, Cold Revenge
If revenge is a dish best served very cold, and revenge is also sweet....is revenge ice cream?
Only if you milk it for all it is worth, otherwise it is sorbet.
I ran into a similar situation at a previous job. I was asked to transfer archived emails archived on a machine for a coworker who had transferred out of state. The application and method I was given to do this displayed one of the emails in whichever folder was being processed. It happened to pull up one that made it very clear that my coworker was having an affair, that both parties were married, and that she would be working with her new love interest. All in two lines. I finished the transfer and said nothing about it to anyone at work.
As far as I am concerned, the whole thing was an onion ("None ya business" for those not familiar with the term) despite the way Big Brother and Big Business would want us to buy into.