A Death in the Family
Season 1, Episode 10
Beckett: I'm not running a background check on your daughter's date.
Castle: Oh, come on! She says he's quiet, he keeps to himself, and he lives with his parents. Tell me that doesn't sound like a serial killer to you!
Castle: [Regarding Alexis' date] Boy, I can't believe my little girl is going to prom... my only comfort now is the long-standing tradition of torturing the boyfriend.
Beckett: What do you mean?
Castle: You know, the time-honored hazing that goes on in those few moments we share, where he and I are alone, just before my daughter descends the stairs.
Castle: Nope! And now it's my turn...
Ryan: What are you planning?
Castle: Something befitting the name of 'Castle'...
Beckett: (Clears throat) Ahem. What's the deal with men and boobs, anyway?
Castle: Biological. We can't help it.
Beckett: But doesn't it bother you that they're so obviously not real?
Castle: (Pauses) Santa's not real. We still love opening his presents.