Cinderella The Bl summary:

Once upon a time, an adorable and lovely boy named Cinderella lived with his aristocratic single mother. Unfortunately, the mother passed away due to an illness and Cinderella was passed off into the care of his mother's sex friend. Cinderella's new step-father, Tremaine, and his twin sons, Drizella and Anastasia, treated Cinderella like a "servant + pet." Whenever Cinderella made a mistake, they gave him a "punishment." But one day, a party is held in the kingdom...