I was just reminded of the fictional erotic fiction that Leopold Bloom picks up for Molly in Ulysses — Sweets of Sin, by “Paul de Kok” (“Poldy Cock,” if you prefer.)
…and that reminds me that there are numerous references to imaginary literary works in Finnegans Wake. The only one that I can call to mind at the moment is Wine, Woman and Waterclocks, or How a Guy Finks and Fawkes When He Is Going Batty, by “Maistre Sheames de la Plume.”
(The alternate title is something I mutter to myself whenever my thoughts start to turn particularly green – more frequently than I care to admit.)