Chrome automatically logs me on to Facebook?

[Nusaiba]

Whenever I type in facebook . com on chrome. it takes me to the sign in page, but my username and password are already typed in. The 'keep me logged in' box is not checked and I have never checked it. I tried logging on with other accounts and signing out to see if that would stop facebook from automatically saving my username/password, but even when I do that, i log out and my password and username are still typed into the boxes. How can I stop it from saving my username and password? Is it something to do with Chrome or something to do with Facebook? I cannot find anything to undo this on the facebook 'account' settings' and this problem has been going on for serveral months