My manager at the time was a Jewish convert to the Mormon church. He explained that during the crusades, it was not unusual for European Jews to "hide" under the mantle of the accepted faith. They retained their traditions inside the home but, for all intents and purposes, displayed catholic postures and in public. My husband vociferously denied being a Jew but ... hey ... actions speak louder than words! Not one member of his family ever attended church, except for a marriage or funeral ... and, even then!
This was very common in Italy in the cities and towns. What was your ex's last name? Generally, Italians with names including the name of a city, like Napolitano, are descended from Marrano Jews from Spain or Italy. Sometimes, entires cities were populated mostly by people like this, such as Livorno. In general, the towns and cities of Italy are populated by a mixed multitude. If you are looking for pure Romans and Italian Celts and Italian Greeks, look to people from the countryside and villages of Lazio, Tuscany, Umbira, & Abruzzi; Piedmont, Venice, Lombardy and Emiliga Romagna; and Calabria, Puglia, and Sicily respectively. My wife's family is from high up in the Appenines south of Parma. They could easily be mistaken for people from Switzerland or France.
Hermann, you are right. My Nonna's maiden name and her mother's maiden name indicate Greek origins.