"It's the sex," admits Broadway and film star Nathan Lane, when asked why he and his onscreen and onstage costar Matthew Broderick have endured and prospered as one of showbiz's hottest couples over the last few years. "We stay together because of the sex," Lane cracks. "The emotional life is dead now, but the sex is so good I can't let go." And let's just say that the rest of us are more than happy to bathe in the frisky afterglow of Lane and Broderick's onstage connubial bliss.

It's been four and a half years since Lane and Broderick teamed up for the stage debut of the zillion-ticket selling, multi-Tony-winning, showbiz phenomenon that is The Producers, the musical theater version of the hit 1968 Mel Brooks film (which starred Zero Mostel and Gene Wilder) telling the story of two showbiz shysters who hope to cash in by producing a sure-fire Broadway flop. As soon as the Lane/Broderick pairing hit the marquee, tickets sales soared. Then, as the show roared its way to becoming a critical and audience smash, the bond between Lane and Broderick as the millennium's new "First Couple of the American Theater" was sealed.

But this month's big news is the much-anticipated opening of The Producers, coming to a multiplex near you. Yes, the splashy movie version of the stage musical based upon Mel Brooks' film had now been translated back into a film. It's all a bit "meta-"-and terribly exciting for filmgoers all over.

No strangers to film stardom either, Lane and Broderick still felt themselves experiencing the odd task of translating their well-worn stage personae to the silver screen. "Well, we knew the lines already," chuckles Lane. "But we were used to having an audience with these characters, so you kind of have to start over. And it's tricky because this material demands a certain size, and it's even operatic in nature at times. So for the film it became a matter of negotiating between doing bits in a small way in close-up that suit the movie, or giving them the St. James Theater version of it." Broderick concurs: "It felt like doing a matinee on a Wednesday about eight months into the run-but with a very quiet audience," he says of the movie set vibe. "That was a big change, because a lot of the timing and the jokes came from the audience." Persevere they did, however. "There were moments when Matthew and I would look at each other and go, 'Well, here we are, this is it," says Lane. "This is going to be put down on film for posterity, so let's do the best we can."

And fear not: All of your favorite bits are there. The walker-wielding grannies dancing in "Along Came Bialy"; the riotous and wrong-natured follies of the "Springtime for Hitler" number, and of course, Gary Beach and Roger Bart's campy scenery-chewing genius in what may be the feyest film number ever, "Keep It Gay"-which gets appropriately pumped up for the film version. "At this point, it couldn't get any gayer without spontaneously combusting," laughs Lane. Broderick even gets his "I Wanna Be a Producer" number turbo-charged, as his onstage bevy of eight chorus gals gets supersized: "I've got 20 dancing girls with me now-it's very exciting."

High praise, surely. And who's to say the celluloid pairing of this Producers pair might not inspire similar enthusiasm. After all, their chemistry and rapport is pretty unbeatable-even off-screen. For instance, when each was asked to reveal a secret about the other, Broderick responded cutely: "Nathan's very good at whiffle-ball. He can hit and pitch very well; he has excellent hand-eye coordination." Lane's answer? "I'm not supposed to say it, but Matthew's gay. He's really gay. He's much gayer than I am. It wouldn't take much-a couple of drinks. He's very agreeable." While Lane laughs, Broderick dryly quips: "Well... Listen to her."

Most married folks should get along so well.
The Producers (Universal Pictures) is in select cities December 16, nationwide on December 25.