When being walked by Anno, if you access the "best pet" branch, choose "ride dick", and select "anal", the text will make multiple references to her penetrating your vagina even though you selected anal. After using Dr. Lash to remove my character's vagina to test, this bug does not appear when you only have anal as an option (there correctly referring to entering anally in all instances I could see), meaning the issue is with selecting anal while you have vaginal as an option.