reflexive text:

Denis Diderot's This is Not a Story (1770) begins: 

'When one tells a story, there has to be someone to listen; and if the story runs to any length, it is rare for the storyteller not sometimes to be interrupted by his listener. That is why (if you were wondering) in the story which you are about to read (which is not a story, or if it is, then a bad one) I have introduced a personage who plays as it were the role of listener. I will begin.'

(cf. Tristram Shandy)

In "The Garden of Forking Paths", 1958, from Labyrinths, 1964 (see also "The Library of Babel"), Borges "imagines a novel in which the path of the story splits, where all things are conceivable, and all things take place. The author of this story within a story is judged insane and commits suicide, and Borges' narrator is arrested and condemned to death - thus the fate of the narrator and of the author in the interactive era is prefigured. It is not hard to see how the task of writing interactively might drive an author to insanity and suicide. Interactivity implies forking paths and each pathway must be written and fitted together. The greater the number of pathways, the greater the sense of textual play for the reader, and the greater the amount of work for the writer. The volume of story web increases exponentially with additional points of interaction." 
(Richard Barbrook, http://mahrc.ac.uk/kids/MA.theory.3.2.db)