Seon Neomji Maseyo, Abeonim!

How can her one-night stand be her student's guardian? Amelie escaped her life as an abused housemaid and became the youngest professor at the Royal Academy. When a prophecy reveals that the person she marries will die an untimely death, she decides to spend a passionate night with a handsome stranger before succumbing to her destiny. However, she is shocked when she comes face to face with her one-night stand again, for not only is he her student's guardian, but he's an unrelenting duke who will stop at nothing to win her over. Will the star-crossed lovers beat destiny and find their happily ever after?

(Source: Pocket Comics)