They're going to kill you Kate, and if you don't care about that...
Castle: They're going to kill you Kate, and if you don't care about that, please think about how that's going to affect the people who love you. You really want to put your dad through that? What about Josh?
Beckett: And what about you Rick?
Castle: Well of course I don't want anything to happen to you. I'm your partner, I'm your friend.
Beckett: Is that what we are?
Castle: You know what? I don't know what we are. We kiss and then we never talk about it. We nearly die frozen in each others arms, but we never talk about it. So no, I got no clue what we are. I know I don't want to see you throw your life away.