Thinking about my stepdad

Ever since i was nine years old, hes been like a dad to me. Even though my mom and him divorced a couple years ago, he never treated me any differently. He is such a good person, and i know im lucky to have him in my life.
IDK why i can't think of him without being turned on. i feel like everyone knows.
He seems nervous around me lately.
I have dreams of him every night, and I fantasise about him all day. I've never even kissed a boy. I hate myself. Im a terrible person.