Undeleteable bookmarks that I never saved

Home screen > long press > Add to Home Screen > Shortcuts > Bookmark > A list of bookmarks pops up titled "Choose a bookmark" - I never saved these and I don't want them there. They are embarrassing sites that I don't want other people to see but there's no way to delete them. You can't find them when you open FF normally and look at your normal saved bookmarks. You can't find them anywhere else in your phone. FF has saved them in some secret black box location that I don't have access to and this is bullshit. If you can't tell me where these are and how to get rid of them I'm dumping FF off my phone forever right now.