how much is too much?

Some people are private, choosing not to bare all about themselves or revealing confidences. Others thrive on sharing personal information, sometimes the most intimate facts, and have no problem divulging information that has been entrusted to them.

i once had a friend who would regularly tell me the most intimate details of her sex life with her now ex-husband. i was uncomfortable hearing this, but never said anything to her because, of course, i didn't know what to say.

What do you say to stop someone from saying too much?