When it comes to online womens erotica unfortunately not any pic of a naked guy will do you would be better off going direct to the audience you are trying to reach and askig, perhaps a quick post over at
http://www.womenseroticanetwork.com or
http://www.femalewebmasters.com is what you should do to find these places especially as both of the urls mentioned have a high level of 4 women marketers on board
