The CEO's Other Woman

Have you ever fallen in love with someone that you can't be with? Someone you can only love from afar?
But what if one day you wake up in that someone's bed?
Then, you realize that the one you have fallen in love with is someone far different from what you've imagined.
"Be my woman" the CEO said.
When your life have turned upside down because of one night. When you realized that the man was your sister's boyfriend as he said in front of everyone in the company,
"She's my woman, my fiance"
Will you rather be the villainess and break off your relationship with your sister, the original female lead or choose the man.
What if one day you wake up in the novel you have just started reading? What will you choose?