I think it'd be great fun to write an erotic novel that starts out as the sort of melodramatic suburban S&M-lite that apparently goes down a storm with middle-aged women and then very gradually morphs into this hallucinatory, Burroughs-esque homoerotic body-horror or a snufftastic Sadean rape-fest. You could publish it onine, chapter by chapter, to get people hooked, then gradually crank up the weirdness.
i have definitely had this idea before
have yet to follow through