Malibu- Mega-diva Barbra Streisand and television actor James Brolin might be millionaires many times over, but don’t expect them to pay $20 for a pair of movie tickets.

Arriving at the Mann Agoura Hills 8 near their Malibu estate on Friday night – apparently to see “Mission: Impossible III” – the 64-year-old singer-actress and her 65-year-old hubby wheedled their way into free seats by schmoozing the teenager in charge.

“We asked especially for you,” Streisand cooed to the young man at the customer service desk, as Brolin smiled a winsome supporting-actor smile. “We haven’t seen you in a while,” La Streisand went on.

The flattered young man said he’d been transferred briefly to a different Mann multiplex, and added: “You’re always welcome here. We’ll take care of you.”

Then he waved the happy couple past the ticket-takers.

Unluckily for Babs and Jim, the transaction was witnessed by paying customer Jennifer Grossman, a fellow Malibu resident and self-described “subversive right-winger” who doesn’t much care for Streisand’s Democratic politics.

“I just couldn’t believe it,” Grossman told me yesterday. “It’s one thing to be comped their tickets, but it’s quite another to ask to be comped, in order to save a lousy $20 bucks. But she’s notorious for being this way. I wonder if she goes to Ralph’s in Malibu and asks if she can have her groceries for free.”

Yesterday, Streisand’s PR rep said it’s customary for “major stars” to get into movies for free. “It’s a professional courtesy that many theaters extend to film stars.” But Mann’s doesn’t have a policy of comping celebs.

Tom Cruise’s rep, Paul Bloch, declined to comment on the Streisand freebies, but did crow that “M:i:III” had grossed $213 million worldwide as of this past weekend. “It was Tom’s biggest non-holiday opening.”

No thanks to Streisand and Brolin.