The horn fifths, fanfares, and horn solos in Fiordiligi's aria Per pietà, ben mio from Mozart's Così fan tutte illustrate the polysemy of opera buffa's musical topics rather than a straightforward correspondence of topic and text. I contextualize my analysis of Per pietà, ben mio by first considering how the pastoral may recall the past, the horn's signification of the cuckold, and horn fifths in the literature. Then I show how the horn fifths topic, as a signifier of the hunt, appears throughout Così fan tutte to suggest cuckoldry. Finally, I analyze the horn fifths and fanfare topics, along with the horn solos, in Per pietà, ben mio in light of their opera seria setting within an opera buffa. The meanings in Per pietà, ben mio are situated between the extremes of the overwrought buffa parody aria and the showpiece opera seria rondò.