He is my Forbidden Fruit.

Cassandra thought she didn't have a family anymore. But then discovers she about her real father, and he takes her under his custody. She must live with him and his family and adjust to a new community, school, and family. There is more she has to adjust to: love and lust. It would have been easier for her to handle these feelings if Cassandra wasn't feel like that towards her step-brother.
*Don't want to offend anyone. Please if talking about taboo things makes you uncomfortable, not a good story for you. Rated R.*