Any other hints about Castle's upcoming Christmas episode? — Melissa
ADAM: The episode, titled "Secret Santa," once again plays on the hush-hush relationship that Castle and Beckett have (pretty much unsuccessfully) tried to keep from their colleagues. But creator Andrew W. Marlowe confirms that the secret will officially be out soon. "We're going to move beyond it. There's only so much storytelling we can sustain," he says. "Capt. Gates is certainly the big issue. How is she going to react? Is that going to threaten the partnership?" So will that reveal be a Christmas gift to viewers or a big lump of coal? "[We] will be dealing with the good of the holiday season — and the bad," Marlowe teases.
Source: TV Guide