It seems that, in general, most people respect that there should be some privacy between partners. However, the degree to which people feel comfortable about sharing various aspects of what goes on between them can differ from person to person. You could be involved with two people and one of them doesn't care what you share about them to your other partner and might even get a little thrill if you share stories about your sex life with that person, and even wants to know what you and your other partner are up to. And then the other person could be totally protective of any information you might share and would be totally offended if you did. So the key, as always, is to communicate and find out what people are comfortable with.
There have been other threads on this topic, which you may find relevant:
I posted a few links in our Golden Nuggets section on "Master Thread - links to other threads worth reading." Go here: http://www.polyamory.com/forum/showt...746#post137746