You can be forgiven for not having heard about this one. At least in philosophy, this text is still (undeservedly) very obscure indeed. It's something I discovered a few years ago during a period of research on the topic of love: I pulled down the entire shelf in the library, looking through each book one by one in search of insights beyond the usual classics (Plato, Augustine, Kierkegaard...), and only ended up making a serious study of about half a dozen of the titles there. Even in that minority, Tullia's dialogue was the only one I ended up reading cover to cover. And I really haven't shut up about it since.
There are precious few really, *really* good philosophical works on love, and this little text is right up there with the best of them. Its discussion centers itself around the question: "Is it possible to love within limits?" This occasions a nest of other topics: what is love, exactly?; are "love" (the substantive noun) and "to love" (the verb) the same thing?; what could it mean for something to be within (or without) limits?; and does God need to be dragged into this at some point? And all of this gets played out in a playful, witty banter between Tullia herself and her (fairly smitten) admirer and man of letters, Benedetto Varchi.
No need to have read the text in advance (although used copies come cheap), as we'll be reading - if not *performing* - the whole thing aloud before we discuss it. Really, what better preparation are you going to get for the 14th?