It's the predinner hour at Billy Baldwin's house, and the father of three is a man in demand. Two-year-old Brooke, clomping around the Beverly Hills rental in high-heeled slippers and a pink princess costume, needs Dad's help adjusting her tiara. Daughter Jameson, 7, presents him with her math homework to check. His son Vance, 5, clamors to get in on the action until his father steps outside to toss a football. Baldwin's cell phone rings: It's his wife, singer Chynna Phillips, asking him to meet her at a furniture store to check out some French antiques for their temporary nest. Jokes Billy's big brother Alec of all the wholesome domesticity: "His life is sort of like Little House on the Prairie."

A 12-year marriage, evening homework sessions, minimal controversy: No wonder this Baldwin brother jokingly describes himself as the white sheep of the Long Island-bred clan that includes actors Alec, 49, Daniel, 47, and Stephen, 41. Now, more than 15 years after he headlined movies like Backdraft (and famously bared his behind in Sliver), Billy, at 44, is back in the spotlight on the ABC series Dirty Sexy Money. But while he's still an unmistakable Baldwin (from the gravelly voice to the passion for politics), he has avoided the kind of headlines his brothers have generated; instead he has quietly cultivated a life that revolves around his wife (a member of '90s pop sensation Wilson Phillips) and such "classic daddy things" as coaching Little League. "The thing that concerns me most as a parent is can I slow everything down?" says Baldwin. "It's going too fast. We're having the time of our lives."

Says Phillips, 39: "He thrives on the insanity of it. He likes the chaos. If it were up to him he'd say, 'Let's go for one more!'" For now, adds Phillips (who is writing songs for a Christian album), "three's a good number."

Sixteen years after they first met, the pair "still have this chemical, electrical thing that passes between us," Baldwin says. But he admits maintaining the relationship takes work. "She'll sit down with me, like a business meeting, and say, 'This is what I'm not getting from you. You need to get better at this.' We communicate pretty honestly." Billy has always been an open book, says Phillips: "He's incredibly emotional." He even cries watching classic baseball clips, she adds. "He's such a sap."

While things with Phillips are solid, Baldwin likens his relationship with his famous siblings to a stormy marriage: "There's a lot of love and a lot of wars." Billy says his relationship with Alec is "getting better again" after years of strain: "He was so sucked up in the vortex of maintaining the relationship with Kim [Basinger, Alec's ex-wife] that he didn't realize it was causing him to neglect other relationships that were important to him." Billy has "issues of trust" with Daniel, whose struggle with drug and alcohol addiction has included nine stints in rehab. "He's doing great. He has the biggest heart and best intentions. But when you've been doing this for 20 years ... I'm thinking, 'Is the other shoe going to drop?'" And Stephen, the born-again Christian youth minister (and Bush supporter)? "He's having a positive influence on the lives of a lot of kids," says Billy, an outspoken Democrat. "Do I agree with everything he's doing? No."

The Baldwin household in Massapequa, N.Y., also included two sisters, Beth, now 52, and Jane, 42. Billy, the fourth of the six siblings, was known for remaining neutral in the tight-knit but sometimes contentious family. "Billy was Switzerland. He was Jimmy Carter," says Alec. "The others could be going at it pretty bad, but Billy was always the peacemaker." (Dad Alexander, a high school history teacher, died in 1983; mom Carol was a homemaker.) Billy studied political science at SUNY Binghamton and worked as a model before following his brothers into the acting business.

After a string of high-profile movies (he scored the Thelma and Louise role that put Brad Pitt on the map, but had to pull out because of conflicts with '91's Backdraft), "opportunities shifted. Things got quiet," he says. So he worked steadily on low-budget and indie projects and devoted himself to charities like the Carol M. Baldwin Breast Cancer Research Fund, founded in honor of his mom, a cancer survivor. (For this month he organized an online auction offering items such as a walk-on role on his show: www.charityfolks.com/bald win). Now on Dirty Sexy Money, an over-the-top prime-time drama, he has a role to die for: a slick politician with a filthy-rich family and a secret transgender lover.

Taking the part meant moving his family from New York to L.A. "My 2-year-old can speak five words—Mommy, Daddy, dirty, sexy, money," Baldwin says. "It comes out of her mouth, like, 10 times a day." Even outside the house, it's one of the most talked-about fall shows. Still, Baldwin worries that if it doesn't last, he'll be left "not knowing if I'm going to work again for 18 months." Turning his attention to things like Little League and wayward princess tiaras eases the insecurity. "I try to take a deep breath," he says, "and just remember how lucky I am."