Found out my best friends wife had cheated on him because she came in the lab where i worked for a blood test which showed he was clearly not the father of baby. The other time was also in health care where I found out a married neighbor in a prominent position had got a young girl pregnant. Both adulterers begged me not to tell. I counseled with a manager in both cases, and was told not to lose my integrity of confidentiality. Both situations have never come out here over 20 years later, and it was the right move.