Four times in which Kevin Ryan is caught being an adorable Daddy.
Javier and Kevin go to Comic Con as their Brotp. Sherlock Holmes and Dr. John Watson, but not without some bantering of course. (Can be seen as gen or pre-slash)
A scene I thought was missing from the episode. When Kate doesn't know if she's ready or not for marriage, she goes to the one person with experience and who she knows well help. Ryan/Beckett brother/sister fluff galore. Spoilers for 6x14, Dressed to Kill.
When Alexis starts going out with a new boy, Castle knows he is nothing but trouble. He promised he wouldn't spy on her date, but he never said anything about Ryan...