stopping others seeing who you friend on facebook?

[skwiji]

Is it possible to stop someone else from seeing when i add or am added by someone on facebook, in other words i want to prevent the "*my name* is now friends with *other person*" from appearing on other peoples or more specifically someone in particulars news feed.
ok Kamen Rider thanks however im not sure if this will stop the 'is now friends with' appearing on "their" "news feed" rather than "mine".
basically my girlfriend has a habit of doing the 20 questions every time i am added or add someone so its just easier if it dosnt come up. it dosnt appear on my news feed or timeline, but still on her news feed.