Logging out of Guest Account

If I accidentally click to login as a Guest (Web or Android), how do I log out and into my actual account? When logged in with my account, there is a logout option in the Account Preferences, but not when logged in as a Guest. I had to clear my browser history (or cache in Android setting) to be able to log back in. Sounds silly, and I would have never thought about it until I actually did it.