A former sister in law was not even reproved for an affair, was told to break it off. She just got sneakier. To top it off an elder I know bragged about what good friends he is with the fornicating new husband.
In the 1970's I stumbled across a very respected elder having an affair with a very respected sister.
I told one of the service committee - he said 'we think that affair has being going on for over ten years'.
When it was obvious that the elders were going to do nothing I threatened to go to the co - the elders gave the couple a private reproof and then told me off for not telling the presiding overseer about what I had uncovered so he could have kept the matter private.
Within six months the couple were at it again and the presiding overseer just sent the sister to another hall without informing the elders there what she had been doing - in fact he gave her a glowing testimony.
Before I could do anything they both then eloped together, leaving letters to their marriage partners.
Finally their original hall had to grudgingly disfellowship them...