It's not you, Luke. It's her.

Garcia (Kirsten Vangsness) hasn't been the same since her baby boy, Morgan (Shemar Moore), left the BAU on Criminal Minds last season, and poor newbie Luke (Adam Rodriguez) has felt the brunt of her grief.

But as Rodriguez tells TVGuide.com, Luke gets it. "He understands where it's all coming from," he says. "She doesn't have anything personal against him."

Their quasi-antagonistic banter has already produced such awkward moments as "fingering techniques" (not like that) and nicknames like "Mr. Tall, Dark and Blandsome." "I really love the chemistry Garcia and Alvez are building based on 'she will have none of it' and he's just trying to through the day," Vangsness says.

Criminal Minds: Kirsten Vangsness gives us a set tour, pauses to mourn Morgan

But one nickname you definitely won't hear come out of Luke's mouth is, of course, Morgan's sacred "baby girl." (I mean, Luke's a smart guy. He knows better than to step on that.) "I don't think he's ever gonna say 'baby girl,'" Rodriguez says. "I don't think he should."

Watch the video to see what else Rodriguez and Vangsness say about Luke and Garcia's relationship.

Criminal Minds airs Wednesdays at 9/8c on CBS.

(Full disclosure: TVGuide.com is owned by CBS.)