Now that you mention it.... it *would* makes sense. I mean... you'd have to have some kind of trick to survive Castle on a daily basis.
Kate didn't properly defend herself, and we know what it lead to: First she got annoyed, and then she got seduced. (damn you, Richard. :P)
Kevin has developped this geeky/slightly starstruck bond with Castle (they're the Mulder to Espo and Beckett's Scully).
Javier probably chose to block it out. *pictures a very Lanie-like wave of hand in front of face accompanied by a "Shhh!" or something along the lines of this.*