Synopsis: My Happy Ending Plan as a Side Character I Refuse the Villainess’s Bad Ending!

The culprit who turned her twin cousins into villains by appearing in a side story of a novel! ...Who would have thought she would be reincarnated as a villainess? I sighed deeply and made up my mind. ‘Let’s raise the twins with love and prevent their darkening!’ I don’t care about the novel and get along well with the twins, but the second male lead, whom I had no reason to get involved with, keeps getting more and more obsessed with me! Ah. Where did it go wrong? And why did the second male lead turn dark when I was just trying to stop the villains from turning dark? “Please, please don’t back down anymore. I don’t know how much longer I can endure it.”