For me its a lack of social responsibility NOT to tell
People nowadays have no compassion for others or desire for something to be "just"
Cheating on your spouse is morally wrong and if you don't want to get found out, don't do it!
It is important that people care enough about the victims of this selfishness enough to act.
Its all ok saying its none of our business...well it is our business to help someone out who is being made a fool of and who is being put in physical danger (std's etc). Also people wasting their loyalty and their life on someone who is a cheating b*stard.
I've been at both ends of the spectrum....when I was single (and newly divorced and screwed up) I had a very brief affair with a married man and I deeply regret it BUT I WISH SOMEONE HAD TOLD THE WIFE because this guy was promising me he was leaving her and never did. At least if the wife had found out the whole thing would have come to a head and been sorted out and I would not have been led a merry dance by the guy.
I've also been in the position where my husband left for another woman and I hated the idea that people knew and I'd been made a fool of.
Sirona