Beware of the Villainess!

I transmigrated as the villainess of a novel.So, what if I’m a villainess?As the daughter of a Duke = I am rich and unemployed!I am just going to live a leisurely life...That was until I witnessed my fiancé, the Crown Prince, having an affair right in front of me.I shed tears when I saw him laugh with another woman in his arms...I did not reveal my emotions, but instead, I asked him with a bright and happy expression on my face.“Are you the son of a b*tch?”She was dropped in the world of a novel and she planned on overthrowing the original novel’s plot