Hmm, I can believe that Hebikawa would want to drag people down to her level to prove to herself that everyone's like her deep down. However, i have trouble believing that she would verbalize it like this. It makes it seem like she thinks she's the bad guy in her own head.
He already knows she's pretty from other people's reactions when the basket came off while they were on a date that one time. He just doesn't know the details yet.