Esposito: Bro... What was that?
Castle: What was what?
Ryan: Your girlfriend just uttered a sarcastic remark about your ex-wife, and all you're gonna say is, "What was what?"
Castle: Oh, that was nothing.
Esposito: Spit it out!
Ryan: Tell us!
Castle: Ahh, OK, uh, as you know, Beckett is, staying at the loft while her place is getting fumigated, Alexis is home sick as well, and then Meredith showed up and she said she wanted to stay in the loft...
Esposito: And you said no. [Pauses for reply.] Tell me you said no. [Look of concern on Castle's face.] Wowwww!
Esposito: Letting an ex stay with you when you're with someone else... That's like throwing gasoline on fireworks!