Receipt: He may have billions in the bank, but the Facebook CEO shared a bargain meal with his wife
The photo of Mr and Mrs Zuckerberg taking in Michelangelo's frescoes was just one many sightings across the Italian capital of the notoriously private social network founder.
Polish tourist Darek Rusajczyk posted the image to Twitter after spotting the social network billionaire and his wife, who is training to become a doctor.
The couple were dressed casually, with Zuckerberg in his typical jeans and t-shirt (but missing a hoodie) while Priscilla wore bright red skinny jeans and wraparound cardigan.
They were snapped listening intently to a guide explaining the marvels of the stunning 500-year-old paintings that adorn the walls and ceilings.
The couple's 32 Euro bill - equivalent to $40 - was also posted on the internet by Italian news websites and Mr Pavoncello said: 'They seemed like two lovebirds. They shared a plate of artichoke ravioli in the centre of the table. It was a very romantic scene.'
With Facebook's value plummeting just days and billions being wiped off its share value after it was launched, perhaps Zuckerberg was looking after his holiday cash during his break in the Italian capital.
Later the couple were spotted in Pierluigi's restaurant where staff revealed they dined out on a supper of prawns Catalan style, oysters and fish carpaccio, followed by lobster pasta and flame grilled fish washed down with a bottle of Chardonnay Gaia e Rei.
Unlike Nonna Betta, staff at Pierluigi were rather more reluctant to reveal the cost of their dinner but it was thought to be in excess of £120 - service not included - with a waiter saying: 'It was just the two of them.
'They were happy and content. They had an intimate and romantic dinner.'
Besides the Vatican were also spotted at the ancient Colosseum, as well as taking in the sights, sounds and colours of the Trevi Fountain and Spanish Steps taking photographs every few minutes.
The couple are thought to have arrived in Rome by private jet and stayed at the luxury five star Portrait suites hotel close to the Spanish Steps which is owned by the family of fashion designer Salvatore Ferragamo with prices starting at 800 Euro a night.