How can we define the feelings of Mr. Dees toward Katie? I want to write a long paper to reject what Mr. Dees said—a fatherly love. Can you explain this in detail?

In Lee Martin's The Bright Forever, Mr. Dees has taken a special liking to Katie, who is only nine years old. He uses a lot of excuses to describe his feelings for her, defining them as "fatherly love." Because Mr. Dees doesn't have any children of his own, he argues that he's displacing those feelings onto Katie.
Katie goes missing early on in the novel, and Mr. Dees is set up as a red herring. The reader is meant to think of his feelings for Katie as inappropriate, the way he fears her parents would see it. As a reader, we're led to assume Mr. Dees wants to keep Katie as his own and that that may be the motivation for her kidnapping.
At the end of the novel, we learn that it's actually Raymond who killed Katie. He knew that Mr. Dees was afraid of people finding out about his love for her. To protect Mr. Dees from this anguish, Raymond kidnaps and murders Katie.
Throughout the novel, we're never blatantly told the true nature of Mr. Dees's feelings for Katie. We only learn about the details through Mr. Dees's own narrative, and we're consistently directed to believe that he's an unreliable narrator.
While we can't know anything for sure, it's hard to imagine that Mr. Dees indeed had simple "fatherly love" for Katie. Their power dynamic immediately puts him in a position to take advantage of her, and if he cared about her as a father, he would remove himself from a situation that might be dangerous or unfair to her. Furthermore, if his feelings were as innocent as he claimed, he wouldn't have to hide them from anyone else. Mr. Dees's behavior does not support the notion that he cares for Katie as a father—rather, he has an unnatural obsession with her that, while it may not be sexual in nature, is inappropriate at the very least.