Never mind what exactly a$$-painting is (or how good it must feel); the point is that Leoni's got gale-force energy, which is just the reason that director Joe Johnston picked her to hold the screen with Jurassic Park III's next generation of computer-generated dinosaurs. It's a part she took not because of the film's blockbuster status, but because the plot revolved around a missing child, and it struck a chord in Leoni, who's got a 2-year-old daughter with the aforementioned butt-naked hubby, David Duchovny.

When Leoni met with Mr. Showbiz on the Universal Studios lot in Los Angeles, she looked ready for a hike, in tight jeans and a white sleeveless blouse. Settling in for a spirited interview, she spoke about motherhood, romance, and, of course, the a$$-painting incident.

What did you think of hubby David Duchovny's butt-baring in Evolution?

Well, you know, we did some a$$-painting recently.

With your kid?

No, not with our kid! What do you think we are? It did not involve children.

Explain, please.

I was the paint loader of David's a$$ — and I say that because I want a little credit. Frankly, I don't think he could have painted as well [without me].

What did you paint?

You don't exactly paint with your a$$. Well, really, you do paint with your a$$. Oh, what you do is load up the person's buttocks. I don't mean "load up." Let me say, just pat it in a general area and use different color schemes. You can imagine what will happen when you take the canvas and sit on it. And when he did sit on it, some were the perfect sit, some of them we spanked a little bit, no smearing because that didn't seem like such a good idea. We put them up for an animal rights auction, [the slogan of] which is "Meat. Don't eat it, paint with it."

Did the paintings sell?

I think we got 3,500 bucks for one.

Did you paint also?

No, no. I loaded, he a$$ed.

I heard you got special treatment on the Jurassic Park III set because you're a mom.

[Smiles] Yeah, I did get special treatment and I got to go home early. But it was five months of filming. My daughter was from 16 months to 21 and a half months.

What surprises you the most about being a mom?

 Everything. I mean, really, you're not ready for it. People tell you it's going to change your life and that is the stupidest thing. Let me tell you right now, if a friend of yours is going to have a baby, don't say, "If you have one, you're not going to believe how much it's going to change your life." Like, duh! Like, every aspect of your life changes. And you're just blessed. You just get it. All that odd self-consumption from "How am I going to pay my rent?" to your own health or whatever, it all goes out the window. You see how silly it is.

So you know why, in JP3, a parent would put his life on the line to save a kid.

I knew that even when I was pregnant. Then a part like this comes up and people say this is my new No. 1 nightmare — which is my child would go missing specifically on an island with dinosaurs? OK, that was not my nightmare. Mine was leaving my daughter on top of the car when you go get your Starbucks and drive off. But that idea, I recognized it immediately.

Weren't there several scripts?

Yeah, and "Not really done yet" was Door No. 3. Still, I felt very secure in accepting this role because no matter what they throw at me, I'm still a mother trying to get her son home safely.

Has being a mother changed the way you approach your career? Are you still as ambitious as you once were?

I think Hollywood wanted me more when I was 26 and I didn't want it then. [Because] I didn't really like what I did. It never felt good, it felt really painful and really scary and I didn't like the process. I was always scared — and listening to those fears. Then I had the baby and it's kind of like you're untouchable. What will they take away from me? Will they tell me I can't make movies anymore? OK. Suddenly I was in there without so much fear — and these are stupid fears anyway, it takes all the fun out of it — and suddenly I was working with no holds barred. Like, this is my time and this is what I love.

So you're ready for a half dozen kids now?

See, it's funny. If I had my way about it, yeah, a half dozen would be pretty good. But that is spoken like the true mother of one. I don't know, we'll see. Once you've been through it, you look at it like, "I've been blessed and I hope it happens again."

On this movie you had so many changes.

Not of clothes.

Not clothes, but scenarios. Joe Johnston, the director, said he wouldn't have blamed you if you'd walked.

 Again, I went into this to play a mother who lost her child. That's such an incredible through line, there wasn't much they could throw at me. I did say to Joe, "I don't want to be the girl going up Mount Everest with the cappuccino strapped to the sherpa's back. If that's what you want, don't hire me. I'm not going to do it very well. I'm a tough son of a bitch." And he said, "I swear to you that your lip gloss is off by the second page." I said, "Great! We're on the same page."

Usually the star is made up to look beautiful.

With this it was, "Can we get some more dino shit?" They smear it all over you. It was fine.

Did you say, "Add a bit more here?"

I did, actually. You can ask the makeup people. I swear to God I was always, "I do not nearly have enough dinosaur shit on." The thing was it would not stick after a while. It was oatmeal. It was good. Every night I'd gross people out by eating it.

This looks like a very physical role. Are you an outdoor girl?

Did you get sympathy from David when you got home?

 No. He doesn't feel sorry for me. [Smiles] Of course, he was absolutely sympathetic. Very sweet. You do work it. You come home and say, "Oh, baby, that's sore there. Oh, yeah, right there." He has done physically challenging roles. In The X-Files, that was no slouch series, he'd come home banged and bruised.

What's it like having him home now that he's done with the show?

The truth is, between Evolution and the press tour, which just finished, we're just now getting to breathe. We both got home on Saturday.

Will you get into it if, or when, JP3 does a lot better than Evolution?

Oh, God, no. Because we're married. What's good for the goose is good for the gander.

But you hear about the dangers of the Hollywood couple.

I've heard that. I'm not being naive, but god#$%*, that's weird. That's really weird. What is that about? If your spouse is doing something and doing a great job, really cooking, it doesn't mean you're not going to. If anyone believes your 15 minutes in town is going to stay, come on, get a grip.

But this is a town filled with competitive people.

I know that. Everybody is going to eat you up and spit you out and you're going to be good for a day and then they're going to slam you out, because now you're an easy target. Come on, everyone knows the gig. You're up, you're going to be shot down and then maybe you come back up again. Everyone else is there to rip you a new one. You better hope the man or the woman in bed with you is the one to say, "Baby, I think you did great."

Or, "Let's go do some a$$-painting."

That's right! That's why we did it, we know how to have fun. Don't let anybody tell you otherwise. For anyone who says we're kind of boring — we a$$-paint.

Do you want to work with David?

I would never want to act with David. Not as a team, nor as a romantic interest, whatever. Because I don't ever want to look him in the eye and tell him a white lie. I don't like that. We have a pristine relationship and I don't want to do that.

It's acting.

It doesn't matter. I don't want to play that game.

It doesn't work anyway when real-life couples team.

I liked Far and Away with Tom Cruise and Nicole Kidman. I thought they had great chemistry. It's just that I don't want to sully anything in there. Am I dying for David to direct me again in something? I can't wait.

David directed you in an X-Files episode.

And we had a great time that day! Garry Shandling is one of our best friends and we had a blast. David is not a yeller, he's got an incredible way of giving direction. He's very calm and in control.

You seem to have the same sense of humor your husband does.

We do have the same sense of humor. He's quicker. D#$%, that guy is so funny.

What's the most romantic thing he's ever done for you?

 He knew my voice is something I'm very shy about because it was this low when I was 6 and that's weird. A cute little 6-year-old looks up, and it's like The Exorcist. It's not right. But my dream was to have been a singer. For my birthday, David rented a music studio with 10 musicians and he dropped me off and said, "Baby, it's yours for the night. Rock out." It was great because he'd told them songs he'd heard me sing in the shower, "Angel From Montgomery" and "Delta Dawn." There were a couple of songs of Dory Previn they couldn't find the arrangements for.

Will we hear this?

You won't hear this CD, that wasn't the point of it. We have a couple of drinks and [decide], "Let's bring out that tape and rock."