Daniela Ruah and Eric Christian Olsen are huddled very close together, and things are starting to get extremely warm.

That’s because the NCIS: Los Angeles scene partners have gathered in the tiny non-air-conditioned bathroom of an L.A. apartment building, down the hall from where their next scene from the CBS drama is setting up. There, they are hovering over a publicist’s cell phone to speak with TVLine about the episode airing this Tuesday at 9/8c, in which Deeks and Kensi pose as husband and wife to suss out a Russian sleeper cell in a suburban nabe.

Again, the quarters were cramped and the heat index high during this 2-on-1, so if they seem to get punchy… well, that’s married life for ya.

TVLINE | It was back in January when Shane Brennan first told me about this “married” episode. Were you filled with anticipation waiting to see the actual script?
ERIC CHRISTIAN OLSEN | [Sarcastically] I was so excited I’ve hardly been able to sleep.
DANIELA RUAH | Eric wishes we were a married couple, so this is the only way he’s ever going to get it. [Laughs]
OLSEN | Wow. Gee, that’s a fantastic quote. Let’s use that.
RUAH | Fine, Eric – “I love you.”
OLSEN | Use that, too! I think it’s awesome because it’s a pretty big departure from a lot of the episodes that we’ve done, and yet it drives storyline as these two characters are forced to go undercover and play this married couple. And there’s a great speech from Hetty that talks about how the dynamic changes just based on proximity, which is true. There are some pretty fantastic scenes between the characters that are really fun to play. The end result is fulfilling as far as what the audience wants.
RUAH | I’ve been told by people who’ve seen the final edited version that there’s more comedy involved than in other episodes. There’s definitely a different tone.

TVLINE | What can you say about “Melissa” and “Justin,” the personae they create for themselves?
RUAH | Honestly, Kensi has an immense amount of fun with this. She’s playing a character that she’s probably not really ever go to be in real life, because she’s an agent. We have a very sort of Desperate Housewives-like lifestyle, we’re very couple-y, there are cute dresses, she bakes cookies for her neighbor…. Plus she just loves undercover work. So she’s having fun with it, and at some point she talks about how she thought she’d hate being a “married “couple, and it turns out she’s enjoying it — and it might be something she wants in the future.
OLSEN | Mostly because she’s in love with Deeks.
RUAH | Ha!
OLSEN | We find out that my character loves running in short shorts — because, yeah, that happens. I decided as a character choice that I’m go to run around the neighborhood to do surveillance but I’m not go to wear traditional shorts. I’m going to go with the short shorts.
RUAH | They’re not that short.
OLSEN | They’re pretty short. I’m showing a lot of thigh. What, you wanted them shorter?
RUAH | No, I think they should have been Spandex.
OLSEN | It’s fun, because Deeks definitely sees opportunities to kind of push it, the relationship, because it’s under these false circumstances. He kind of puts her into positions that lead to some pretty interesting things that would never happen in real life.

TVLINE | That was my next question. What lines of intimacy need to be crossed as part of keeping this cover?
OLSEN | There’s initially an argument because you’ve got to sleep in the same bed, because if [the bad guys] have any sort of heat sensors or cameras or microphones planted or something…
RUAH | …we have to play a married couple all the way, as far as anyone else is able to see. So obviously within that there are…
OLSEN | … a lot of lines to be crossed.
RUAH | Huge lines. And they’re crossed.
OLSEN | By both characters.
RUAH | Deeks is pretty cheeky, but I agree – lines are crossed by both characters for sure.
OLSEN | You say “cheeky,” some would say “charming.”
RUAH | Cheeky, charming, tomato, tomahto.

TVLINE | Are there plentiful PDA moments for “Densi” fans to enjoy?
RUAH | I don’t think we should reveal any of that.
OLSEN | You don’t want to talk about the PDA moments?
RUAH | I want the audience to be surprised.
OLSEN | But by saying that they’re going to be surprised, doesn’t that mean there will be some? Isn’t that what you’re hinting at?
RUAH | No, not at all. [She pauses] OK, I get smacked in the butt once, by Deeks.
OLSEN | That wasn’t the moment I was talking about.
RUAH | And she doesn’t punch him in return!
OLSEN | But that’s what we’re talking about, the circumstances that make it impossible for her to do what she’d normally do. Because if we weren’t undercover, she’d knock him out! He knows she has to play that role, and in turn there’s something that Kensi does to Deeks that completely throws him, and it will leave a lasting impression with everybody who watches.

TVLINE | Turning serious-ish, will this fuel any real talk between the two of them? Do they have a “moment” at the end of all of this?
RUAH | There’s a moment where they’re sitting down on the couch and Deeks brings her a bag of frozen peas because she got hurt, and that’s when she talks about what I said before – how she thought she would hate all of this. But she actually likes it. It’s comforting and nice. So there are definitely moments where they get serious with each other.
OLSEN | I think the best version of a relationship as it matures is two characters that are kind of discovering each other and themselves through that relationship, and this is a good example of that. Every episode has elements of that, and obviously some are more light-hearted, but even in those we put our defenses down and you see who these characters are at the end of the day.
RUAH | Or even who you would like to be. You live a certain lifestyle, and then you see this other lifestyle, and it becomes something that they may want in the future — with or without each other.