Dich heimlich lieben

On the wedding night, the female protagonist discovered that her husband had an affair and was abused and unconscious by a mistress. After being discovered by the male protagonist, he provided assistance. After waking up, the male protagonist hid his identity as his ex husband's second uncle and wanted to use fake marriage to gain his status in the family. At the same time, he expelled her ex husband. However, during the process of getting along, he found out that he had truly fallen in love with the female protagonist