Two old pros show the kids how chemistry works in the romantic comedy "And So It Goes," a love-the-last-time-around romp that’ll give its target audience the warm fuzzies.

Diane Keaton and the perfectly coiffed Michael Douglas, who plays her grumpy Realtor neighbor, fight, flirt, annoy and court like it’s 1979. This Rob Reiner comedy has the Oscar-winning heir to Hepburn and the Oscar-winning Son of Kirk in grandparent mode, a couple of spry old-timers forced together when the grandkid he never knew moves in, and prefers the company of the neighbor lady who cannot stand him.

Oren Little (Douglas) is waiting on that last big sale before retiring in tiny suburban Bristol, Conn. After 44 years in the business, he’s selling his priciest listing — an $8 million mansion that was his home. Widowed, he drives to showings in his vintage Mercedes convertible, himself immaculately turned out, the house immaculately staged. It’s overpriced, but telling him that sets him off.

His neighbors, in the charming waterfront fourplex he’s downsized to, have to contend with his rudeness, selfishness and general boorishness, which his second martini only accentuates.

‘AND SO IT GOES’ Rated: PG-13 Opens Friday

Leah (Keaton) is a widowed lounge singer who fronts a jazz combo (Reiner plays the toupee’d piano player) who cannot get through a set without talking about her late husband, and weeping. The tactless Oren is the last guy she’d be interested in, age-appropriate or not — even after Oren shares his own widowhood woes.

But when his estranged, ex-junkie son (Scott Shepherd) shows up and drops Oren’s granddaughter, Sarah (Sterling Jerins), on Dad as he heads off to prison, Oren’s crankiness endures its toughest test. Leah steps in and that throws the two adults together, awkward though his pick-up lines eventually turn out to be.

Working from an undemanding Mark Andrus ("As Good as It Gets") script, Reiner steers closer to his old big-budget studio picture form. His players know how to land a laugh, and he fills in around the leads with choice character player support. "Jersey Boy" Frankie Valli plays a club owner who might book Leah, and the great Frances Sternhagen is Oren’s only friend, a fellow Realtor who lets a few cute codger cusswords fly in between puffs of her Camel Unfiltered.

It’s all adorably light, aside from the odd, jarring moment when Oren has to face the ultra-realistic addicts of his son’s former life. And the players are never less than game.

Mercifully, the movie isn’t about the child. But the jokes and comic situations never aim higher than "cute," and often fall short. Oren is kind of a half-hearted ogre, and Keaton’s Leah is half greatest hits performance, half wardrobe.

Still, seeing these veteran players go through their paces, find their comic rhythms and probe for laughs where many a laugh has been found before is not a bad thing.

Review by Roger Moore, McClatchy Newspapers