Scenario IV for Kronologic – Paris 1920

The Paris Opera is organizing a big evening, bringing together a crowd of guests under its dazzling gilding and sparkling chandeliers. Among the guests are two lovers who, despite the proximity of their presence in the same place, will never cross paths, separated only by destiny and the murmurs of the Opera.
During this evening, only one male/female couple ever found themselves in the same room (even in the presence of other guests).
Who are the star-crossed lovers?