On Monday night's much-anticipated wedding episode of Castle, our favorite non-couple have a little chat about numbers. No, not the square root of pi ... That number. "You sign women's chests at book readings. You cannot be shocked that I'm not a virgin," Beckett quips. Priceless! Original Air Date: Castle Season 4, Episode 11: "Till Death Do Us Part" airs on Monday, January 9, 2012 at 10 p.m. ET on ABC.