There are very few women duets or trios in Roman comedy. That’s why we can study how they work. This paper focuses on the duets which seem to be debates where two women compare their views. What matters in these duets is not what the women say (as a matter of fact, opinions don’t remain after the duet), but the way they struggle for being the show leader and the best player. As they follow conventional patterns, female duets have also a dramatic function : they are used to create a singular character or to stage an unusual situation. The conventional duet between a meretrix and a lena follows the same rules, being a ludic duet and a meaningless debate. The Plautus’ Persa’s scene between parasitus Saturio and his daughter, a uirgo in a meretrix disguise, is a variation on this meretrix-lena conventional duet.