Marriage? He Loves His Younger Brother so Much

Under the age of 20 + double cleanliness + double secret love + slightly yandere + childhood sweetheart [The rich young master + the rich lady] [Ancient book restorer + fake serious female forensic doctor] In the eyes of outsiders, Mu Yanqiu is recognized as a proud daughter of heaven, with a good family background, good grades, and a good career. The only imperfection is her husband who is not doing his job properly. Mo Tinglan is a young master from a wealthy family who is not easy to worry about. He has always had a morbid and dark thought in his heart. He has liked his brother's fiancée, his future sister-in-law Mu Yanqiu, since he was a child. A sudden marriage, her sister-in-law became her wife, and her brother-in-law became her husband. She always knew that he liked her, but she didn't know why he suddenly didn't like her. What Mo Tinglan didn't know was that she had already fallen in love with him, and they had always had a two-way crush. He thought that the eldest brother was blind, but God opened his eyes, but he didn't know that this marriage was requested by her, and her husband could only be him. Mu Yanqiu wondered why people's hearts were so fickle, and why his promise to marry her when he was a child was not counted, but he couldn't escape. He was her husband, and she would not teach him to escape even if she was locked up with a chain. After repeated trials after marriage, the two-way secret love finally gradually surfaced.