During the fifth season of Dexter, Detective Debra Morgan has really come into her own. At first it seemed like she was falling into all her old traps: messing up at work, getting down on herself, and falling for the wrong guy. But as we near the end of the season (the penultimate episode airs this Sunday), it’s clear this is the year everybody’s favorite potty mouth grows up. We sat down with actress Jennifer Carpenter, who plays Deb, and asked her the big questions: What’s the deal with Quinn? What would happen if Deb found out the truth about Dexter? And who is really responsible for Deb’s profanity-laden, hilarious one-liners?

Where do you see Debra as we near the end of this season versus where she was a year ago?
I think the evolution of Deb is a little louder than most of the characters. Dexter is actually trying not to evolve in a weird way, he’s trying to find his beginning. On the other hand, Deb has sort of been fast and furious and doesn’t seem to have an edit button. And suddenly, this season, she has a private life, or at least private thoughts — she didn’t expose everything. The show felt a little less emotionally driven than it had in the past and I think it worked in my character's favor. It left room for me to do my own sort of coloring on the side; I didn’t have to show all my cards every week.

Deb is currently pursuing the barrel girls’ murder case, and if she finds out what really happened, Dexter could be exposed. What would Deb’s reaction be — and you might already know this, we don’t know how this season ends — if Deb found out who Dexter really is?
I think my answer to that changes day to day. There’s a part of me that thinks that Deb bleeds blue, and she’ s a cop through and through and she would put him away. And then I realize that without Dexter she has no link to her childhood — there’s no witness to recount stories and remind her of her origins. For that reason, I think that she might make a deal with him. I'm just grateful that, at this point, five years in, that decision is not in my hands. I have a sense that the writers and producers have an idea of how that will unfold, and I’m ready to know. I feel like the audience has earned it as well. I feel like it’s time for them to find out.

What makes you think the writers are considering letting Deb know the truth?
I think it’s kind of heading that way. I also feel like I [Deb] have a lot of really integral puzzle pieces to the picture of Dexter — there’s a lot of stuff that’s difficult to ignore. I mean I’m supposed to be able to know when people are lying, when they’re hiding something, and I’m really good at my job. But I can’t see the writing on the wall in front of me? Especially after I was dating a serial killer? I think it’s time.

But that’s what we love about Deb, she’s such a great combination of badass and naive good girl.
I think she knows once something is seen it can’t be unseen. Everything changes forever. She might not even want that. And she deserves all the good stuff. She deserves the brother that she’s always suspected she’s had. She loves him. She loves his potential. She sees his potential. She wants him to engage.

She set him and Rita up.
Right, but then she was never really invited to engage. Poor Deb. Poor, poor Deb. You know, it worries me sometimes that she’s got a gun on her back.

The thing that happened this year with her killing someone — there’s the scene in her kitchen ...
I love that you call it her kitchen.

It’s her fucking house, man!
Thank you! Deb goes 100 miles an hour in one direction — forward, forward, forward — and she sort of surprised herself, she switched gears a little. I think she was shocked that she didn’t feel anything [when she killed someone], 'cause that’s what she does — she emotes to a fault. And there are a couple of things coming in the next episode where you see her — she’s suddenly no longer in the shadow of Harry, she’s finding her voice, professionally, finding her voice and admitting where she is, that things aren’t quite black and white. She might bleed blue, but she knows there’s got to be room for some gray. She might do better at work if she admits that the choices aren’t always so clear.

What’s up with Deb’s terrible taste in men?
Here’s the thing. She was denied affection from every male figure in her life. Her brother, her father — they just walked right by her. So when a man gives her attention, it’s as if she charges through every cautionary flag that exists and can only see the light of the love and attention that they’re giving her. When those cautionary flags are in her face, she’s in trouble again. But that’s Deb’s addiction. She’s addicted to any form of attention and love. When I first heard that Quinn and Deb are gonna be a couple, I was concerned, but you know they have a lot in common. They can compare scars together and keep each other clean.

People love Deb’s foul mouth. Are all Deb’s lines written for you or are you cursing like a sailor?
I actually take a lot of the cuss words out.

So we’re not even getting as much as what’s written for her!?
Exactly.

Do you have a favorite Deb line of all time?
We had some criminal coming in during the second season, I think, a really tall gigantic football player, and I called him “a fucking beef bus,” which made me laugh. And I really like “I’d rather put a campfire out with my face.” “Shit a brick and fuck me with it” is also okay.

Do you ever find the Deb cursing infiltrating your regular life?
I was just home for Thanksgiving and I caught myself cursing three times. It was so embarrassing. I was so ashamed.

When I interviewed Julia Stiles [who plays Lumen], she talked about how Michael [C. Hall, who plays Dexter] really sets the tone on set. What is it like to be married to the star of the show? What are the pros and cons of working with someone you’re romantically involved with?
The pros are we have each other’s trust. I would say it’s true about everyone on the cast and crew — we are all connected through friendship, there to take care of each other. [I'm] hesitant to say we’re a family, 'cause it sounds generic, but we’ve all invested in each other, so it’s easier to take risks at work.

People assume it must be hard to play siblings …
You know what? The work is easy. When he puts the khakis and the loafers on and combs his hair that way, he’s not Michael. And I swear, when I put her shoes on and the gun on my back, I’m not the same person. I hesitate to say what the cons are because I don’t want to concentrate on them. The season is fast and furious and then it’s over.