Kieran Culkin clings to 'This Is Our Youth'

Kieran Culkin has earned critical acclaim for stage roles and a Golden Globe nomination for the indie film "Igby Goes Down," but it's still his older brother, Macaulay -- the tabloid-hyped child star of "Home Alone" and other '90s films -- who arguably is more a household name.

That may soon change -- or it sure as heck ought to -- given Kieran's energetic performance in "This Is Our Youth," a Kenneth Lonergan play co-starring Hollywood's fave young bumbler, Michael Cera ("Arrested Development," "Juno") and newcomer (and noted teen fashion blogger) Tavi Gevinson. The play, about 1980s-era, overprivileged, Upper West Side slackers, runs through early January at the Cort Theatre.

Culkin and Cera, friends since co-starring in the film "Scott Pilgrim vs. the World," play roughhousing buddies Dennis (Culkin), a know-it-all drug dealer, and Warren (Cera), his awkward pal with a bag full of $15,000 just stolen from his dad. Yelling, laughs and a little romance (Gevinson) ensue.

Culkin played Cera's role in London back in 2003 and has been obsessed with the play -- and performing it again -- ever since. He chatted with Newsday contributor Joseph V. Amodio.

This play seems exhausting -- your character comes a bit unhinged, and you practically blow a gasket onstage.

Yeah. [He laughs.] I've actually been sick. A cold. The voice is going. My only way to deal with that is to just stretch it as far as I can, go louder and push till my voice totally blows.

Ha! There's a plan ...

SEE PHOTOSCelebs you may not know are related

Yeah. I can't reach that level unless I go too far, and that's the only way. So I spent all yesterday not talking. I don't care about how exhausted I am. I've been trying to do this play for about 12 years. [He chuckles.] I'm just happy to be doing it.

You played Warren before.

And I wanted to play him again. But after a few years, I realized ... I'm not this guy anymore. It took some readjusting in my head to see me playing the other character. I handed the play to Michael just as a, "Hey, this is what I've been reading, it's great, check it out." He read it that night and the next day said, "I think we can do it." There was never a discussion about who we'd play. It was somehow understood he'd be Warren, I'd be Dennis.

Is it easier to play buddies with your actual buddy?

SEE PHOTOSWill Smith and more grown-up child stars

It is. But I'd ... pretty ... confidently say neither of us is like these characters. Not at all. It's funny -- people always think they have an idea of Michael because of characters he's played. What are the words people use to describe him?

Awkward, lost puppy dog- type guy ... ?

Yeah. He's not at all like that in person. At all. He's one of the most confident, smart young men I know.

I love the character we never see -- Valerie, your girlfriend. Your phone calls with her are hilarious. Do you have an image of her in your head?

Um ... I do. She kind of reminded me of a friend's ex-girlfriend. I've changed it, but I'm gonna keep that to myself. I don't want to put that out there into the world.

Sure. I don't care who she is. I'm just curious if you see an actual face.

Totally. There are a few people I speak to on the phone in the play, and they all have a very specific image and voice in my head. Like Stuey... .

The guy from Long Island ...

Yeah, I say in the script how he has a grotesque "Lawn Guyland" accent. He has a very specific look -- somebody I know, but fatter. With that accent.

You're married now, and 31. Does that make it harder to play this age group?

Dennis is 21. I worry I could seem too old. But the moment I get onstage ... I feel 21. That weird in-between spot -- childhood's behind us, adulthood's a step away. Young audiences identify -- they go, "This is exactly what I say to people." And parents listen carefully, too. [He laughts.] They don't want their kids winding up like this.

Must be great, having achieved this goal.

Yeah. I don't know if I'll ever be satisfied. We did it in Australia [in 2012], and I was like, OK -- but I need to do it again. So now I think, "You brought it to Broadway, we're running the show for four months. So ... when it's over ... I might be like, OK, I guess I can let this play go." But who knows? In like 20 years, I'll be fighting to direct it. I'll probably never let this thing go.

What about a movie?

That would be great, too. We were talking about that a few years ago. Who knows? At that point, I'll be 45, still trying to be 21.