From PEOPLE Magazine Click to enlarge
At 9 months old, little Levi Alves McConaughey is unmistakably his father's son. Loves a good workout? Check—he's climbing stairs already. "He wants to be where the action is," dad Matthew says proudly. Wicked sense of humor? Got that, too: During diaper changes, "he gets the joke when he pees on me. He laughs his butt off!" And—uh-oh, ladies—he's "a huge flirt. Camila's like, 'You're just like your dad!'"

For Matthew McConaughey, 39, and girlfriend Camila Alves, 26, parenthood has been "fun hard work," says the actor. With a new romantic comedy, Ghosts of Girlfriends Past, due in theaters May 1, the Texas-born actor says his life has never been fuller. "It's a wild, wonderful adventure," McConaughey says of becoming a first-time father last July. "It's a great new chapter in life, for sure."

From strolls on the Malibu beach to baby-on-board road trips, both Levi and Alves, a Brazilian model and handbag designer, fit into McConaughey's easygoing lifestyle, no adjustments required. As a mom, Alves has a "real strong sense of calm," says McConaughey. "We have a good flow, and neither one of us wants the other one to change. We've both said it, if we did change, that could be a problem! We love each other for who we are."

In his current role as a womanizing photographer in Ghosts, McConaughey gets another try at love with his childhood sweetheart, played by Jennifer Garner, after visions of his exes teach him some lessons. "It was just the best romantic comedy I've read in years," he says. "It had a big heart about having a second chance. And the ghosts in it levitated the comedy and allowed me to just be a fool."

His new family also inspired the actor—already juggling projects including a fledgling record label—to start the j.k. livin Foundation, which targets students ages 12 to 17 with after-school programs that encourage healthy living and building self-esteem. (It and his production company, j.k. livin, are named after a saying he came up with when his father passed away, "just keep livin'.") "In starting a family, you really start thinking about community," he explains. "We're teaching them about nutrition and about those choices that they make."

But McConaughey says Levi remains his "most rewarding production" yet. "I go make films and stuff, but this is the epic that I'm making for the rest of my life," he says. Most mornings Alves wakes up first, then McConaughey arises and makes a breakfast shake: "We feed him some shake, get some music going. He'll stand up on his mom, or my chest, and gets dancing." Levi is learning words in his mother's native language, Portuguese (which McConaughey is also learning), but isn't much of a fan of baby talk. "He's looking at you like, 'What are you doing?' So I just start talking to him, and he'll look me right in the eye with a solid grin and all of sudden he's like, 'Yeah, now I'm talking to you, Dad,'" McConaughey says. "That's really cool."

So is just watching him happily bang a cup against a plate. "You see the wonder in something we see every day," says McConaughey. He and Alves never want that feeling to fade. "We do a lot of the same things, we just take him with us," he says. "We're a tribe now."