It used to be, whenever someone asked me a really rude, personal question, I'd be too shocked to reply. But now I have finally found the perfect response. When someone asks a really nosy question, look at them, smile sweetly, and say, "How much do you weigh?" BELIEVE me, it shuts them up, especially if it's a woman. If you happen to come across one of those rare individuals who don't mind revealing their weight, simply ask them some *other* nosy question they won't want to answer. Like, "How much money do you make?" Or, "Is that your real nose/boobs/hair color"/whatever seems fake on the person! They'll probably respond with shock and say something like, "How dare you?! Why would you ask such a personal question?!" Then just say, "exactly," or "indeed." They should get the hint. Might seem mean, but they asked for it!