In November 2007 Sicilian police reported to have found a list of "Ten Commandments" in the hideout of mafia boss Salvatore Lo Piccolo. They are thought to be guidelines on how to be a good, respectful and honorable mafioso...
1. No one can present himself directly to another of our friends. There must be a third person to do it.
2. Never look at the wives of friends.
3. Never be seen with cops.
4. Don't go to pubs and clubs.
5. Always being available for Cosa Nostra is a duty - even if your wife is about to give birth.
6. Appointments must absolutely be respected.
7. Wives must be treated with respect.
8. When asked for any information, the answer must be the truth.
9. Money cannot be appropriated if it belongs to others or to other families.
10. People who can't be part of Cosa Nostra: anyone who has a close relative in the police, anyone with a two-timing relative in the family, anyone who behaves badly and doesn't hold to moral values.

These appear to be old school values that indicate cheating on one's spouse is highly frowned upon "across the pond". Infidelity sure seems to be more of an American thing with these guys... of course there are exceptions to any rule whether you are a cook, baker or candlestick maker.