How do I prevent firefox from automatically filling in usernames and passwords without completely disabling auto-fill?

I'm an active user of form auto-fill, but I recently noticed it adds it automatically on some sites. Meaning it adds it without me doing anything. For an instance, if I go in on a site where I have an account (note: a single one) and log out, the login is automatically added. Trying to figure out whether or not I can disable it leads me to [this](https://support.mozilla.org/en-US/kb/control-whether-firefox-automatically-fills-forms). The problem being I can only disable it completely, meaning it won't remember anything. I want it to remember forms, but not fill it in without me trying to fill it in. Reproduction is really simple: find a site where you have one account stored in auto-fill (two or more doesn't work; it has to be one) and make sure you're logged out. Go to an applicable login page and the credentials should be added without user interaction. My question: Is it possible to prevent Firefox from automatically filling the form without user interaction without disabling auto-fill completely?