Paying her with his body

Cecilia never imagined that her childhood sweetheart would betray her for her Stepsister.  She aims to fulfill her and her mother's dream of becoming a famous actress. However her Stepmother and stepsister is still out to get her and she had to avoid all her malicious Schemes.
One day, During her birthday which is also thesame day as her Stepsister's, she fell into one of her schemes, she meets a cute but rude little girl and save her. His father offers to repay her with his body. "Marry me!"
Cecilia: (........)!!?
Little Girl: (......)!
That same day, her Stepmother came with a proposal for her to marry someone from an influential family for their family business .Thus Cecilia  accepted the  offer  due to her suffering. Cue lots of Comedy, sweet moments between Cecilia and the Little Devil probably Big devil too.