You may not know someone as well as you think you do, dear Sagittarius. That's why it might be unwise to share something you are planning on sharing. It could backfire on you if the reaction is not the one you expect. Even though it may be tempting to say what's on your mind, you should resist the urge - for now, at least. There could be secrets you are not yet privy to that would make a huge difference in how this person reacts. Play it safe for the time being.