The Girls of San Frediano (1955)

All movie guide:
Plot Synopsis by Hal Erickson
A novel by Valerio Zurlini was the basis of the Italian Le Ragazze di Sanfrediano (The Girls of San Frediano). The story deals with the amorous escapades of handsome garage mechanic Bob (Antonio Cifariello). The first name in Bob's little black book is the tempestuous Tosca (Rosanna Podesta, who that same year played the title role in Helen of Troy). Before long, our hero throws Tosca over for a chorus dancer (Giulia Robini), a schoolteacher (Luciana Liberati) and a dress designer (Corinne Calvet). Through it all, Gina (Marcella Miriani), a girl who lives in Bob's apartment building, silently carries a torch for the grease-monkey Lothario. Just guess who Bob eventually winds up with.
Wikipedia:
Le ragazze di San Frediano (English: The Girls of San Frediano) is actually a 1949 novel by Italian author Vasco Pratolini. The novel is set in Florence at the end of the second World War. The story follows the escapades of a Florentine mechanic, a local "Don Giovanni," who romances several women simultaneously and secretly. His multiple relationships come to the women's attention, and they conceive a plot to punish the mechanic for his behavior.