Credit: Yfrog Photo: Castle Couple Andrew Marlowe and Terri Miller TwitPic

There's a very special delight that comes from the TV world spilling over into the real world (if you make a distinction between the two, that is). Here are a couple of couples that exist inside and outside of the Castle world.

Andrew Marlowe and Terri Miller

Normally, the term "power couple" doesn't conjure an image of two writers, but this pairing might be the exception. Andrew Marlowe created Castle and serves as the executive producer and writer. His wife, Terri Miller, is also a writer for the show. We like to imagine their home life consists of spirited discussions over plot details ("No, no! He should be poisoned with arsenic-laced macaroons!") as they sit at a partners’ desk furiously pulling pages from their typewriters. But they also have two kids, so at some point, they probably pay attention to them, too.

Credit: Jesse Grant/Getty Images Photo: Seamus and Juliana Dever Attend Castle's Season 3 Premiere Party on Sept. 13, 2010

Seamus and Juliana Dever

This couple can be found in the "aw, shucks" file. Seamus Dever, of course, has played Detective Kevin Ryan for three seasons. As a fun bonus, his real-life wife Juliana plays his TV-fiancee Jenny Duffy-O'Malley. So, when Ryan proposed to Jenny earlier this season, Seamus and Juliana were pretty familiar with how that works. (We're guessing Laura Prepon wasn't involved with the real thing at all.)  How convenient! And adorable.