Well, kind of horrible but composed in 1789 or so and Mozart is not responsible for the Libretto (though he did agree to participate in the project).
The short title, Così Fan Tutte literally means “So do they all”, using the feminine plural to indicate women. It is usually translated into English as “Women are like that”. The words are sung by the three men in act 2, scene 3, just before the finale; this melodic phrase is also quoted in the overture to the opera.