By now you’ve either read or heard of Fifty Shades of Grey, the erotic novel that’s taken the world by storm. Perhaps you’ve even read the other books in the trilogy. And even if Christian and Anastasia aren’t your cup of tea, this series isn’t the first to get graphic on the printed page—and it certainly isn’t your only option if you like to get naughty when it comes to your bedtime reading.

Check out the gallery below for nine book series that will have you hot under the collar with the characters’ down-and-dirty antics—as well as have you enjoying the stories that unfold from page to page and book to book.

Warning: Don’t read these books in public in case you turn to a sex scene and find yourself bothered and blushing!