In This Is 40, Judd Apatow‘s sort-of sequel to Knocked Up, Leslie Mann and Paul Rudd reprise their roles as the neurotic Debbie and Pete. Albert Brooks joins them as Pete’s inappropriate, money-sucking father; and Megan Fox wears a bikini. (All in all, great casting.) At the film’s press day, we got the chance to talk to some of the cast members, and talked to us about getting older, improvising and the hardest scene they ever had to film – which involved Melissa McCarthy.

What was the toughest thing about turning forty and how did you overcome it?

Leslie Mann: I think every day is different. Some days I feel fine and other days I feel like crying all day. I have lunches with my girlfriends who have just turned forty and some of those lunches we’re crying and screaming about our husbands saying we want to leave them and run away. And at other lunches, we’re fine and we love our husbands and we are happy with our lives. I’m not sure. I don’t have the answers.

Albert Brooks: I have a different secret. When I was very young, I started to make friends with much, much older people. So when I was twenty, my friends were fifty, and I never really went through forty because I would watch them die and I would feel younger. So you make friends with older people and you will always feel young no matter what. On my fortieth birthday I was in a hospice with a 92-year old buddy – that’s a lie (laughs).

Paul Rudd: I remember, as a kid my dad always told me getting older beats the alternative. Although my dad is actually now the alternative so I don’t know what he would say.

Albert Brooks: The alternative being?

Paul Rudd: Oh he’s dead. He’s completely dead. Think about that for a second.

Megan Fox: I kind of did what Albert did in the sense that I married my husband, who is thirteen years older, so I will always be a trophy wife for him (laughs).

Albert Brooks: It’s true. It’s true.

Megan, were you nervous about coming to set with a close-knit group of people?

Megan Fox: No because from the first audition I went in for – it was Judd, Leslie and Paul – I went in with my sides and we did that once I think, then Judd wanted me and Paul to improvise and have an awkward conversation. So we had to do all of this improv, which I’m not familiar with at all. I was so scared, and it was then that I got over it at that point. There was that one day on set though where Leslie and I did the scene in the car after the club and that was one of those days where I memorized the wrong scene. I didn’t know my dialogue. I was so scared that I didn’t know it that I started to do all of these crazy things in the scene that I don’t know if they worked. I was so scared that day.

Leslie Mann: It turned out well.

Mr. Brooks in your scenes with John Lithgow, were you improvising a lot?

Albert Brooks: In rehearsal we got a chance to add and improvise a bit. That’s sort of the way it works. The idea that you get there and at the actual moment you’re making it up is sort of a fallacy, but you get a script and then you have time to throw that to the wind and see what comes back and then you can set things you really like. So a lot of things were said in rehearsal.

Was Mr. Lithgow compatible with your comic sensibilities or looking for more of a dramatic opportunity?

Albert Brooks: No, he sort of played the guy he was suppose to play, which was a stick in the mud. I think when it was really funny what he really wanted to do was laugh. But once you get settled into your character, that’s how you react. That guy would never be friends with Larry. They would never be friends. He had to act as if I were an annoyance, but he always wanted to laugh. But he doesn’t because he’s in the union (laughs).

How difficult is it keeping a straight face during shooting? What was the hardest scene to shoot?

Leslie Mann: The scene with Melissa McCarthy was the hardest scene to shoot without laughter. That was impossible.

Paul Rudd: Yes, that was really hard.

Leslie Mann: It was the weirdest thing, I had never experienced that. Maybe like one time I crack up and then I can hold it together. But with her it was hours, we could not keep a straight face. And finally we just gave up and Judd said that he was using more than one camera so we could just laugh because we couldn’t keep a straight face.  And the crew was all laughing. It was ridiculous. She is the funniest person ever. She was so great.

Paul Rudd: I’ve seen people in tears before but that was something otherworldly. The crew had to leave the room. It was impossible. She just kept her composure through all of it.

Leslie, your kids do a lot of cursing in the movie. How did handle that on set?

Leslie Mann: For Maude we don’t allow her to curse at home, I know she does at school so it was fun for her to do that at work. Which by the way, I didn’t think was a great idea but Judd thinks it’s funny. So that’s fun for her but then she gets home from work and she tries to use the F word or whatever and we have to shut her down.

Albert Brooks: [My kids] don’t curse that much. I’m from another school of comedy (laughs).

Leslie Mann: Do you think they do it at school? How old are your kids?

Albert Brooks: My son is fourteen and my daughter will be thirteen next March. They don’t curse a lot, but they hear it a lot because everything they watch on YouTube is cursing unfortunately. We don’t do it in the house. If they hear it in the house they do it. But we’re just not a very big f*ck household.

Megan Fox: Do you monitor their Facebook account?

Albert Brooks: My wife ensures there are no Facebook accounts for the kids.

Leslie Mann: But Maude never curses like that in front of us.

It’s brave to have a film called This is 40 because Hollywood tries to direct films towards the 18-24 demographic. Do you feel like Judd’s audience is growing up along with his movies so they are getting to the point where they are facing some of these issues now?

Albert Brooks: This is 40 is only the title for a few theaters. This is 18 is for a lot of theaters.

Paul Rudd: I say we call it This Is Zero Dark Forty.

Paul, Judd has you in uncomfortable positions, like putting your legs over your head basically and face the camera, how do you prepare for that? There’s a mirror blocking the “point of entry.” But is there a time when you have refused to do anything he’s asked of you?

Paul Rudd: (Laughs) That’s an interesting phrasing of the question! Somebody asked me this once before and I’m sure there has been.

Leslie Mann: You wouldn’t take off your shirt when you were sitting on the toilet.

Paul Rudd: Here’s the thing – I’m not excited about any of it. I thought it would be funny but it’s embarrassing and horrifying but in the context of the movie and this is what we are all trying to go for, then I’ll do it. Certainly if it’s funny, there is no room for vanity. I was laughing as I was doing it, as I was drying on the inside. I think the only way you can prepare for a scene like that is with a bottle of Gin.

It’s the same question for you Leslie, is there anything that embarrasses you? Or are you game for anything?

Leslie Mann: I’m pretty much game for anything.

Paul, like your character you’re married with kids, can you relate to Pete’s frustration about life?

Paul Rudd: Oh yeah. Obviously the situations are different but there are certain aspects of marriage and parenthood that seem relatable. We’ve spent years talking about all of this stuff. We’ve all gotten together – my wife, Leslie and Judd have all had dinners and we’ve talked about it. This is going back to Knocked Up too. There many aspects of the character that are very much a part of me.

For anyone on the panel, since Lost is the kids TV obsession in this movie, what do any of you watch on TV?

Albert Brooks: You’re going to get me started here on a stupid topic. You know I watch Homeland, but the last few – I can’t. I’m having trouble.

Megan Fox: Don’t spoil it.

Albert Brooks: No. No. I don’t want to spoil it, but there are just some things they need to fix. But that’s a very good show. It’s just you can’t keep talking on cellphones without people listening. Everything is done over a cellphone, all the key information and it’s the CIA. It bothers me. But I think the acting is great on that show. And I watch that on Sunday. And then I never got into The Wire when it was on. And then I got into it and watched three years of it in two days. It was like eating too much I can’t watch the remainder of it ’cause I watched so much of it. I was glued. I just kept putting episode after episode claiming I was exercising but I wasn’t. I was eating and sitting.

This Is 40 hits theaters Friday, December 21st.