Is there a novel?

There is a book, yes. You can find fast spoilers here:
https://forum.novelupdates.com/threads/the-duchess-lewd-invitation.118535/
And original novel here:
https://ridibooks.com/books/1007029505?_s=search&_q=%EA%B3%B5%EC%9E%91%EB%B6%80%EC%9D%B8%EC%9D%98+%EC%9D%8C%ED%83%95%ED%95%9C+%EC%B4%88%EB%8C%80

Thank you