Jon Huertas Jon Huertas

A sexy Castle storyline I first broke news of this past summer is finally happening. With Castle and Beckett's unconsummated tease expected to stretch out for several seasons, the ABC series is giving fans the next best thing. In the January 10 episode, it will be revealed that Detective Javier Esposito (Jon Huertas) and medical examiner Lanie Parish (Tamala Jones) have been secretly getting in on for some time!

"We find out it's been going on for about eight weeks, so it's still a new thing," reveals Jon, who had been campaigning hard for the storyline. "Of course we try to hide it from the gang to keep things professional, but it's hard for us to control ourselves."

Sounds like it. The Castle set designers erected a whole new house set for Lanie where the couple will do the deed. And to prepare for his bedroom scenes, Jon has been amping up his cardio workouts. "People are going to be seeing a lot more of me than they've seen — and I'm not just talking about screen time," he says. "For some reason they want us to be naked a lot. With Castle and Beckett not being able to get together, they're relying on our characters to play out the sexual element."

You would think after three seasons of working together, it might be a tad awkward for the co-stars to get naked in front of each other. Not so much.  "I was looking forward to it," Jon admits with a playful wink.

While future episodes may out the down-low couple to their co-workers, for now only the audience is in on the romance. But that hasn't kept Jon and Tamala's curious co-stars, Nathan Fillion (Castle) and Stana Katic (Beckett) from peeking in on the pair during filming. "Nathan and Stana are like kids," Jon says. "They're supposed to leave the set when Tamala and I start going at it, but I look over my shoulder and there they are watching and giggling like five-year-olds."

And one last nugget: while Jon says not to expect an Esposito/Lanie engagement anytime soon, Det. Ryan (Seamus Dever) does pop the question to girlfriend Jenny when the series returns January 3. Says Jon, "My character's a little harder to tame."

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