So far I haven't found anything so taboo I won't write it. LOL The time may come but it hasn't yet. I've done f/f and m/m and straight m/f erotica plus my first m/f/f/m menage just came outlast month from Phaze and I have my first f/f BDSM story in the works. Not much bothers me or makes me shudder. I've gotten dark before with a graphic rape scene(not meant to turn the reader on) and still got some heavy criticism that it was too graphic but the story was pushing me to tell it that way and thats what I did. I guess that makes me a bad girl.
KB adds: Beth's discussion list is great if you're into Romantic Erotica.It's an active list with losts of snippets and discussion. I reviewed her Big 4-Oh! for Erotica Revealed this month.