THE KIDS ARE ALL RIGHT is getting a lot of play, and it’s a very good movie without being a great one. No doubt the set-up is grabby: lesbian couple (Julianne Moore and Annette Bening) have two kids, who look up their sperm donor (Mark Ruffalo). He re-enters the picture, this time creating drama in the form of an unexpected romantic entanglement. There’s something a little contrived about the set-up, but there’s real meat on these bones;the script honors the complexities here,provides no fancy answers, and offers a fabulous canvas for some very detailed performances. Moore is the earthy stay-at-home mom, Bening the super-achieving doctor, both of them hilariously PC. Ruffalo gently ruffles their feathers in different ways, and these scenes subtly reveal the cracks in the relationship. There are funny moments of everyday awkwardness, sudden and earth-shaking revelations, and the poignance of a family trying to keep its bearings. It’s a smart slice of modern life.