Emily Prentiss was an impressive woman. He'd known that from the beginning; anyone who can work their way up to the BAU was, but she was something more. She never really opened up when she first arrived, but she put forth excellent work. He'd almost been jealous of her, but then remembered how it felt to be the new kid and put on a friendly face. He grew to like her in short order, and learned just how impressive she was. She was amazing. He'd acted like a complete jack-ass to her and she forgave him. She gave him time and space, while at the same time not letting him slip by. She gave him perspective and a much needed reality check. After that, he started to watch her without being noticed, something he'd learned years ago while still in school. Being invisible has its advantages. He felt kind of bad for doing it and not unlike the UNSUBS that they studied, but he was transfixed by her. He noticed trivial things at first, like the fact that her belt buckle was placed usually slightly to the right on her hip; or that she held her pen in her left hand before writing. Later he began to notice other things. She always listened to what he had to say, or at least gave off the impression that she did. She picked at her nails when she was nervous, or tapped her feet rhythmically. She never once called him "Spencer" and, he noticed, that when she thought he wasn't looking, she was watching him.