(Keeping in mind that you posted this in the BDSM Category.)

Have you read Please, Sir by Cleis Press? It's a collection of short stories available here on EF.

If you have an e-reader, you can peruse the "free" books on that website named after a river in South America. There are always at least a half-dozen erotica titles on the list. I picked up Maid for It by Lucy Rodgers a few weeks ago. (It's not bad, but I wouldn't pay the $3 they're now charging, since it's only about 80 pages long.)

Wicked Desires by Eliza Lloyd is currently free. I haven't read it yet, but the jacket copy sparked my interest and it currently has only 5-star reviews.