Written by actress Rashida Jones (I Love You, Man) and her actor friend Will McCormack (Boiler Room), Celeste and Jesse Forever is an unusual out-of-love story about two people who try to maintain their best friendship despite being unofficially divorced. Although the two writers were never married in real life, the film (directed by Lee Toland Krieger) is inspired by their own relationship, with Andy Samberg playing Will's "part" opposite Rashida Jones as Celeste. McCormack is in the film as a drug-dealing friend of Celeste's named "Skillz." In an exclusive interview, I sat down with the amicable writing duo for a chat about their first film. Amongst many things, we talked about their first produced project, the key to good stoned acting, and we also had a very real conversation towards the end about Jones' perspective on platonic relationships.

Celeste and Jesse Forever opens in Chicago theaters on August 10.

Will, you play a stoner in this movie, and Rashida, you have moments in which you get high and drunk as well. What's the key to good stoned acting?

Jones: With drunk acting, I think the key is to act not drunk. I think anybody will tell you that. Drunk people are trying to make sure you know that they are not drunk.

McCormack: I have a stoned acting trick ...

Jones: What's your trick?

McCormack: Should I give it away? The thing to do is you pretend everyone is just as high as you, or even higher, so that you're all in this world of highness.

Jones: I never act stoned.

McCormack: You were more sad than stoned.

What are some of your worst eating habits when you're in a funk?

Jones: Do I have to be in a funk to talk about my eating habits? [laughs] I stop eating when I'm in a funk.

Do you drink water at least?

Jones: I don't treat my body like a temple when I'm mad at myself, or mad at the world.

McCormack: I don't eat. And then Rashida is like, "Have a snack." And then I feel better. Sometimes all you need is some almonds or a granola bar. Sometimes when you're depressed, you're like, "Oh, I just needed a sandwich." And then I'm fine.

I had read that although this is your first writing project, you've also kicked around other ideas before. I'm really curious as to what those ideas were.

Jones: We can't tell you, because they might happen! The truth is, [when writing Celeste and Jesse] we weren't like, "We should write a movie. What should we write about?" It was like, "I have this idea, I feel like there's a lot here. What do you think?" He was like, "X, Y, Z, this is why it's good, let's do it." We really didn't talk about other things, right?

McCormack: Well, we tried to write that pilot years ago ...

Jones: As a movie. But, when we sat down to write this movie, the premise is why we wrote it.

Was there a lot of moments of you two sitting in coffee shops with a blank computer when writing this screenplay?

McCormack: A lot of coffee shops when we were younger ...

Jones: In our 20s.

McCormack: ... but there was a lot more coffee than ideas.

You wrote this in your 20s?

Jones: We wrote Celeste and Jesse Forever four years ago. We had been talking about writing with each other since 2002. This is the first time that we actually did it.

Do you have more interest in writing more, and possibly directing?

Jones: Both. We're still writing together, and we just finished a script for Universal, Frenemy of the State.

McCormack: And we've been thinking about directing something together, a little [movie].

Jones: Not as little as Celeste and Jesse.

McCormack: This movie was tiny.

But it has big people in it. How do you think the characters would be different if this story wasn't in L.A., and how important is it that this story takes place in Los Angeles?

Jones: When you're doing small budget, you save so much money by going to a different state. Good job, California, good way to save our economy! But it was important to us that it would be in L.A. We wanted to show our version of L.A., which I think is impossible to do in Toronto, which is a great place. [To Will] What was the state that I was like, "What? No way." It may have been Massachusetts, or Connecticut?

McCormack: There was a Canadian version. But to me, even the language [of the film] is so L.A. The feel of it is so West Coast that it would have been a different script. It's a little bit satirical. We love these people, but we're also making fun of them a tiny bit.

Will, how "L.A." is the "Z" in your character's name?

McCormack: Very. Is that real?

McCormack: I actually have two friends that I call "Skills," but they are both with an "S." I added a "Z," which made it totally original. In the film you have some very tragic dating moments. Have you experienced anything like those moments, Will?

McCormack: Like, terrible dating?

Yeah. Rashida has horror stories in the movie ...

Jones: Which are real ...

Can you top that, Will? What happened to her?

McCormack: They happened to me [laughs]. The photographer date ...

Jones: [To Will] You'd be like, "Yeaaah!"

McCormack: Dating is so rough, usually I'm the one who is terrible. It's so uncomfortable dating, because you're trying to be the best version of one's self. So then you're not yourself, because you're trying to be something.

Jones: It's so unnatural. It's bullshit. To me, it has no direct correlation to (A.) Getting to know somebody, or (B.) falling in love with somebody.

How else do you do it?

Jones: They should have Truman Show-like set-ups where you have to work side-by-side with someone, or do something else beside sitting across from each other. So you get to know somebody for real. That's why they have dating shows, I guess.

Jones: You're right. That's the best way to do it [laughs]. Did you guys pick most of the music for the film, or was that something you collaborated with director Lee  Toland Krieger on?

Jones: My nephew Sunny [Levine] wrote the score. He's dope. We wrote the script originally to his first solo album, "Love Rhino," which is a break-up album. We wrote a lot of the songs into the script, but we didn't end up actually using any songs from that album.

McCormack: He composed a lot of music, and he and his partner selected a lot of music. He and Zach Cowie, they have a music collective called the Biggest Crush, they were incredible.

How much did you improvise with Andy Samberg, and what did he contribute?

Jones: We didn't improvise. Getting into the masturbation scene, that was improvised.

McCormack: We had no idea to improvise.

Jones: Even just who Andy is, and who people know Andy to be, contributes a lot to the film. You start in the middle of their story, and you know who Andy is. It bides you a lot. "Oh, that's that guy, slacker, hoodie-wearing, man-child." Right? You can actually go forward, you don't have to deal with the back story of that. But on top of that, I think Andy gives an inspired, honest performance in a way that you've never seen him do before.

McCormack: [To me] Do you like the poster?

I do. I was just thinking that I like his tie. Do you like the poster?

McCormack: I do. It's very simple.

Was it a very intentional to have Ari Graynor drop the bomb about the truth of the relationship in the second scene of the film?

Jones: That's a stolen idea. A friend of Nicky Weinstock, who is a really bright guy, it was his initial idea. He had read the script, and he was like, "What if you do this?" We said, "That's the best idea ever, and we're going to steal it." I wanted to take a convention and give you everything you're used to, the montage with the great couple, and flip it a little bit.

McCormack: Originally we had this thing which also wasn't terrible where Celeste and Jesse both go, "I have something to tell you," and she says, "I think we should get divorced," and he says, "I think we should stay together." But then we changed it to that idea. It's not tricking people, but it's like, "Oh, what? Wait a minute." Rom-coms are so familiar, it's tough to find ways to make them new.

Do you think the idea of platonic relationships is a concept that some people will simply never understand?

Jones: I think it depends on what your history is. If you've been married, I think it's always going to be complicated. I have tons of guy friends that I have never touched.

And have never wanted to touch, either?

Jones: No, I think you always want to touch each other. Because why are you hanging out with them? There's attraction on some level. It's intellectual, emotional, physical, you're going to be attracted to that person. Most of the time those things manifest physically, because we're human. So at some point, you're going to think about making out, or having sex, or seeing someone naked, but, you're like, "I'd rather have them as a friend."

And that requires a sense of maturity to see what's really worth it, I'd say. Jones: Listen. Every moment of our life is a decision to not do something animalistic, right? We're not attacking people on the street, or killing people, hopefully, so why not just be a little bit more civil and have friends with people you may want to have sex with?

McCormack: I don't think that we have control over it. I think desire is desire, and I think a lot of people who cheat, or aren't monogamous, don't intend to, but something happens where they can't overcome it. I'm not sure I'm really in charge of that. I just want to tell any future wife or girlfriend that if I cheat, it's not my fault.

Jones: Oh my god. That's in print somewhere very soon! [laughs]

McCormack: I'm not in charge! I'm not running the show.

Quick Questions with Rashida Jones and Will McCormack

What did you have for breakfast this morning?

Jones: Chicken sausage, whole wheat pancakes, grapefruit. McCormack: Coffee.

Favorite summer movie?

Jones: The first "Batman."

Burton's or Nolan's?

Jones: It's a tie. The Dark Knight too. McCormack: Back to the Future.

If you could be somebody else for 24 hours, who would you be?

Jones: Barack Obama. McCormack: Sorry to be boring, but Barack Obama. Jones: [To Will] Iverson? McCormack: I love Allen Iverson. Or Derek Jeter, in 1999.

Are you a Yankees fan?

McCormack: Huge.

Age of first kiss?

Jones: 14. It was terrible. My first French kiss. McCormack: 14.