Honestly, I was a little shocked at how harsh Castle was to Beckett in that clip. From his tone to body language.

We've seen her go on rants but never in the tone he's used. In fact the two biggest rants she's given she felt embarassed afterwards. Like going to bed after she realized how she went on about him and Shaw. And her rant about Ellie when she thought he was going out with her again even after he knew she used him. He set her up that time and she fell for it. And she knew it by the smile she gave.

I sure hope he has a moment to recognize his jealousy like Beckett has because he was real ugly in that clip. Thank goodness she called him on it because he shouldn't get away with such behavior.

If he keeps that kind of attitude up during the episode and it carries over to the finale no wonder the working relationship is tense.