Is there any novel recommended where the female protagonist transmigrated into the book and became a supporting actress, and was kept by the male protagonist?

The female lead transmigrated into a supporting character in a book and was kept by the male lead. It was worn before the male protagonist and the original female protagonist got back together. After that, the original female protagonist wanted to get back together with the male protagonist, but at that time, the male protagonist had already fallen in love with the female protagonist. (Originally, the male lead would have gotten back together with the original female lead. The original female lead was just a supporting actress.) I hope those who have read it can tell me the title!