i hate this.

Bottom Line
There is only so much you can do to ensure confidentiality, so focus on prevention.

In Detail
Your social circle is not drawn with a solid line -- perforations in the infrastructure cause a few leaks. Secrets will be spilled, and you only have so much power to ensure the confidentiality of words that are already uttered -- it is totally out of your hands. So instead, focus on prevention. Choose your words wisely and limit your comments.