Starring Annette Bening, Julianne Moore, and Mark Ruffalo. Rated 14A. Opens Friday, July 16, at the Fifth Avenue Cinemas

Things aren’t too bad for the young ones in The Kids Are All Right, a wonderfully satisfying new domestic comedy from director-cowriter Lisa Cholodenko, who similarly limned an even more skewed clan in 2002’s Laurel Canyon.

Teenagers Joni and Laser (Mia Wasikowska and Josh Hutcherson) don’t mind that their parents drink coffee from identical World’s Best Mom mugs. But there has been increasing distance between successful doctor Nic (Annette Bening) and the earthier Jules (Julianne Moore), who has drifted from job to job.

Trouble was brewing before our sensitive half-siblings tracked down the previously anonymous sperm donor who fathered them both. Mark Ruffalo plays this reluctant dad, a roguish restaurateur called Paul. The kids are drawn to his stubbly, motorcycling ways. And Jules, currently searching for her inner landscape architect, gets unglued when Paul hires her to move his bushes around.

This is probably the best role Ruffalo has had since his breakthrough turn as the brother in You Can Count On Me. In fact, this could be the same guy a decade later, on the cusp of getting it together but still careless with everyone’s feelings, including his own. Cholodenko’s ear is superbly tuned to the dynamics of intimacy, and the inarticulately passionate Paul is a needed foil for Bening’s jabbering control freak (she’s the out version of that wife in American Beauty), with the unfocused Jules caught between personalities to mirror.

If the central folie í  trois provides much of the drama and almost all the humour, Kids begins and ends with the well-being of its children, as suggested by the Who song it’s named after. The movie has a sharp tongue and a very big heart.