@nissi Well a spoiler
Spoiler!
Duke fell for her as antonio just was denying it but when he found out about her being a woman he started seducing her and she fell in love with him in chapter 84 of the novel they did it and chapter 85 a rumor started because they did it while she was disguised as antonio that duke is gay and they can't reveal FL is a woman because of her real identity
I like to post spoilers for the stories I find interesting because I don't have much time to read novel due to busy schedule
you will find me in most romantic historical manhwa comment sections 
you will find me in most romantic historical manhwa comment sections