La noche más hermosa (1984)

Federico, a senior Spanish TV executive, a man of talent and innate skills for business and diplomacy, begins to suspect that his wife Elena, an excellent actress who retired prematurely after marriage, deceives him with another man. The symptoms are that Elena sighs, looks a lot at the sky and is aware of the exact time a comet passes that appears only every hundred years. In other words, she is waiting for her "most beautiful night".