Megane Koushaku no Hatsukoi to Jimi Reijou no Kusare Kansatsu Nikki

In order to get rid of his relatives and daughters who want to take over the family, Duke Evald organizes a fake marriage with Lydia, the count's third daughter, in exchange for her debts. But, what the duke doesn't know is that she has a dark side: she is a "popular rose (BL) novelist" who observes Evald and fantasizes about BL stories. Her behavior is different from that of other young ladies, and gradually Evald becomes interested in Leadia...