Callen may have to spend his NCIS: Los Angeles Christmas revealing his true occupation to his girlfriend.

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Hetty's (Linda Hunt) team works hard to keep their jobs from their family and friends (unless your Sam, of course), and Callen (Chris O'Donnell) has skillfully kept Joelle in the dark since last season.

Unfortunately for Joelle, TV Line reports that Callen's other half will find herself caught up in a major software theft during "Humbug," and NCIS will need to step in to protect her life. Something tells us Callen won't be able to do his job and maintain his cover at the same time.

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"G Callen reveals secrets w/Gunfire & Romance. Merry Xmas Ep. airs 12/15/14," teased executive producer John Peter Kousakis on Wednesday.

Meanwhile, Sam's (LL Cool J) family will have a surprise of their own. The Former Navy SEAL's teenage son will be back in town for the holidays, and it will be the first time viewers are introduced to the older Hanna child.

Find out more when NCIS: LA airs Mondays at 10 p.m. ET on CBS. Click the video below to see a preview for the series' next episode, "Traitor."