I haven't personally read anything other than "Stranger in a Strange Land" for poly fiction, which was good but not "sexy" really.
I found the following links though:
http://www.sirenpublishing.com/polyamour/
http://www.polychromatic.com/fiction2.html
Hope that helps! I'm just heading to work now but I will check for more later if you like. (gotta live up to my username! :P)
-booklady78