Please add option to turn off update sharing with each post to avoid mass embarrassment.

Sometimes I respond to a news article, health article, etc but then my activity shows up on friends' pages. The thing, is a lot of what I am posting is completely irrelevant to them. Would you please add a button when posting that allows me to choose to share or not to share a particular post with friends' updates? My aunt asked me about these random things she reads that I've written, to my complete embarrassment. In the mean time, I think I've turned off all sharing except contact info. Still, it's unacceptable that I don't have the option to not share my current update with contacts.