Crane reminds him of Jan van Eck which is probably where his instinctive vitriol comes from. The man being the worst person he's ever met, but gentle and pleasant and sharp as a tack, vicious in executing his plans. The man was made of ice, happy to murder his own son with a polite smile. It may be unfair to project someone like that on another, but it's a consistent feeling of his.

"Are you calling me pretty? How sweet." It's funny how with most people his flirtatious tone is used in fun, and with Crane it's almost like poison, because he knows it annoys him. "I think your crush is misplaced though, Doctor."