you can disable the auto sign-in feature in the Account settings - Links tab - Automatially activate account after loading option. If you disable this option, your saved login and password will be inserted on the site but Sticky Password won´t automatically press the login button. So you can manually choose the security question and then sign in.
Or you can disable Sticky Password for this site by adding it to the list of the Ignored web addresses (Settings - Ignored web addresses). This option can be used if you don´t want to add an account for this site to Sticky Password database.