I can’t remember the title of this danmei I read a while ago. It was a transmigration plot where the mc gets put into the body of a novel’s scum gong. The story starts with him awakening in that body at the wedding altar with the main shou. I’m pretty sure someone had also transmigrated into the shou’s body, but that wasn’t revealed immediately. The antagonists are the shou’s family I believe, mainly a white lotus brother who the OG scum gong was having an affair with according to the original plot (?) or something along those lines.

The soul that transmigrated into the scum gong body had read the novel and was determined to treat shou properly - the soul in the shou was weary of him because he had also read the novel. Over time they develop a cute bond and are super loving. The conflict near the end happens where the soul in the scum gong’s body returns to his original world back and forth for a while. In the end both the souls who transmigrated into the novel go back to the real world and find each other there. The author of the novel is revealed to have been the gong’s sister.

Sorry if that was super long, I appreciate any help!