In the raunchy comedy Bad Teacher, Elizabeth Halsey (Cameron Diaz) is a teacher who just doesn’t care about anyone but herself. She’s foul-mouthed, ruthless and wildly inappropriate, in her pursuit of the fake boobs that she’s convinced will make her more enticing in winning over a rich, handsome man. Waiting for her meal ticket to take her away from her day job teaching middle school, she sets a plan in motion to win over Scott Delacorte (Justin Timberlake), who unfortunately starts to fall for Elizabeth’s colleague Amy Squirrel (Lucy Punch), setting her jealousy off into overdrive. Meanwhile, gym teacher Russell Gettis (Jason Segel) expresses interest in Elizabeth, even though he won’t take any of her bullshit. Completely the wrong person to help guide students, Elizabeth’s schemes get more and more outrageous, shocking everyone around her.

During a press conference to promote the film’s release, co-stars Cameron Diaz and Justin Timberlake, who has proven himself to be a very talented comic actor, talked about centering a film around a character who is horribly ruthless and yet still somehow likeable, their own experiences in public school, filming the hilarious dry-humping scene, and the importance of chemistry in a comedy ensemble. Check out what they had to say after the jump:

Question: Cameron, in the film, your character does and says some horrible things, but you still like her. Did you have to work really hard on that?

CAMERON DIAZ: That was the great thing about this movie. There was not one ounce of energy spent trying to make anything about this character likeable. It was genius. It was what I loved about this. I went 30 pages into the script and thought, “There’s no way I’m playing this character! How could I ever redeem her?” And then, 10 pages later, I was like, “I think I like her! This is amazing! I don’t have to apologize.” There’s no apologizing. That’s the beauty of this script. It is such a breath of fresh air. You usually spend the last 20 minutes of the movie, apologizing for what the character did in the first hour and a half. People are just afraid of just owning it. In life, we don’t just have an epiphany and change our life. It happens, but it’s not the norm.

Your character is pretty ruthless, in her effort to have breast implants. Were you able to identify with that at all?

DIAZ: Obviously, if I thought I could get somewhere by having bigger boobies, I would have done it by now. For her, it’s everything. It’s called hard economic times. You can’t find a millionaire, like you could three or four years ago, before the crash. It’s a lot of work for her now. It’s an investment. Suzie Ormond would have been like, “Girl, that’s part of your five-year plan.” She’s working hard for those. She thinks that, to get what you want, you have to invest in your business, and hers is bigger tits. I’m not judging her, but if we really believed this was the right thing to do, we wouldn’t be making fun of it, right? It was really fun to make fun of her. We all know what it’s like to come up against people who have different priorities. She focuses on the wrong things. It was great to go to work every day with a team who was on the same wagon, going towards complete and utter distaste, and throwing everything out the window. We had a lot of fun doing that.

Are you products of the public school system?

DIAZ: I am as public as education gets.

JUSTIN TIMBERLAKE: We have to figure out a way to pay teachers more. That’s my opinion of it. They are surrogate parents, away from home. The teachers we actually learned more from taught us life lessons more than trigonometry. They have such a huge responsibility and are under-appreciated and underpaid.

What teachers did you guys have that resonated with you, whether good or bad?

TIMBERLAKE: I had a teacher in seventh grade who told me I should have more realistic goals than songwriting and entertaining. My schoolwork suffered. She can suck it!

DIAZ: I had a teacher, Mr. Fujikowa, in sixth grade, who used to come in after the weekend and tell us about his 3-year-old son. He would say how wonderful it was to teach your son and pass on your knowledge to him, and that you want to encourage your kids and teach them life lessons. As he sat with his feet kicked up on the desk, he talked about how his son was starting to walk and how gratifying it was to see him take the four steps up the stairs to the porch, to get to the front door. As he got to the very top last step, he would pull on the string that he tied around his son’s leg, to bring him back down to the first step. I just thought that was the most amazing thing. I laughed so hard. Everyone else was horrified, but I was like, “That’s awesome!” That really shaped me.

Was there any worry about having a sexy teacher as the main character, given the news about teachers having affairs with students?

DIAZ: The one thing that Elizabeth Halsey doesn’t do is take on a seventh grader. I would not be down with that. That would be a different movie, clearly.

The dry-humping scene is hysterical and perhaps the only one captured so effectively on screen. Was that difficult or weird to film?

TIMBERLAKE: Well, I do think we have the only dry-humping scene captured on film. Jake [Kasdan] was my humping coach. I’ve got to say, there’s nothing wrong with a good jean jam. Cameron and I felt that we had a responsibility to young people, who are going to buy tickets to Transformers, and then sneak into this movie because they’re underage. It really is a public service announcement for safe sex. No one ever got pregnant with their jeans on.

DIAZ: It was absurd! That’s pretty much the only message in the movie that we are proud of. Other than that, there’s nothing else. We thought we shouldn’t just be making a movie about nothing that is of any importance. If we are trying to be role models, in any way, we should at least offer up a jean jam.

Justin, you get to sing in the film, but it is the most ridiculous song. Did you get to contribute to the lyrics at all?

TIMBERLAKE: “Simpatico,” the original composition from Scott Delacorte, is a special song. That was an idea that Jake [Kasdan] came to me about. In the script, it was a loose idea about the teacher band, and Scott doing a singer-songwriter thing. I remember Jake coming to me and saying, “We have to create something that is going to be terrible.” It’s pretty obvious that I put my body on the line for comedy, so why not my voice? Honestly, the lyrics were the screenwriters’, and I just tried to create the most terrible melody that I could. It had to be so bad that they could not market it in the trailer. It’s really just an extension of the character. It was a total collaboration between me, the writers and the director.

Cameron, you were in The Sweetest Thing a number of years ago, and There’s Something About Mary, and now Bridesmaids is doing really well. Why do you think it’s the time for women to behave badly and be funny in movies now?

DIAZ: My commitment to it is pretty obvious. Women have always behaved badly, probably worse than men, but maybe men just don’t have the stomach for it. They don’t want to see it on film because they just can’t take it. Any of my guy friends, when I tell them what women really talk about, they can’t take it. At this moment, it’s time for women to come out and be themselves and be accepted. There are a lot of those films now, where audiences are willing to laugh at those things. This movie would have been just as hilarious with a male lead as a female, which is great. It just goes to show that humor is for everyone. I think we can find a lot of similarities in what we laugh at. I think people are willing to take a chance, and studios are now willing to formulate new things. We’re tired of seeing the same things. After awhile, it just doesn’t work anymore. This is a business. We want to make some money and make things that work.

TIMBERLAKE: As a male who enjoys those dirty things that women say, I think funny women, like Carol Burnett and Madeline Kahn, have been around forever. There have always been genius female actors in comedy. I also think we live in an age where technology has afforded a generation more of a crass look at the world. Directors want to push the envelope, but in a way that can get laughs. That always fuels the engine.

How did you guys craft your amazing chemistry?

TIMBERLAKE: After the first rehearsal and the first orgy, we all felt right together.

DIAZ: It’s like comedy marksmen. Everyone is precise. They pull back the arrow, take a breath to slow down the heartbeat, and then let go, and bullseye. You have to do that, on a comedy like this. You are constantly shooting, and you never stop. Jake [Kasdan] would come up to me and give me notes. It’s precision comedy.

Justin, you’re in line to join the five-times hosting club of Saturday Night Live. What makes a host a good fit for that show?

TIMBERLAKE: I’ve hosted four times now. The season finale was just my fourth time, although it does seem like more because, when I’m in New York City, they can’t keep me out of 30 Rock. I grew up with SNL. It is an institution. It is part of the humor and chemistry between me and my father. I come from a divorced family. I didn’t get to spend a lot of time with my father when I was young, and it was something that we share that is really special to me. Growing up with that show, I remember staying up late, which was really bad parenting because I was too young to watch some of the jokes that were on it, but I turned out okay. I’m just such a huge fan of the show. To be honest, I owe getting the shot to be in Bad Teacher, with these genius comedians and comediennes, directly to SNL and Lorne Michaels, for letting me be there.