As most people who read the mainstream press have recently learned from a spate of glowing reviews and reports of record-topping box-office numbers, the premise of new film The Kids Are All Right begins with two long-wed lesbian moms named Nic and Jules (Annette Bening and Julianne Moore) who live a privileged lifestyle in sunny California and, as married couples often do, have a pile of picked-at psychological scabs and power imbalances. One day Laser and Joni, (Mia Wasikowska and Josh Hutcherson) their teenage kids with quintessential, but no less poignant, teen angst, decide to contact their shared sperm donor through a blind phone call. The donor, Paul (Mark Ruffalo), turns out to be a dudely type with an organic restaurant and an aversion to things like settling down and finishing school–but something about his newfound biological offspring touches him, and vice versa. Soon they’re hanging out, helping him in the garden, and beating him at basketball, and he’s having dinner on the family deck, sparring and bantering with “moms.”

SPOILERS AHEAD

If this were a fit-the-mold quirky indie film, the next two hours after the above setup had been established would serve to comically preach about how awesome it is to have a weird and random assortment of people in your family, and how love is blind to traditional structures and expectations: let’s throw it all out the window and harvest some chard! And it’s true that The Kids Are All Right, directed by Lisa Cholodenko, has the kind of sharp writing and winning cast that elicits the expected indie family drama emotions, both hearty guffaws and subsequent sobs. In a packed New York theater, filled with a former Republican mayor and countless straight and gay couples and families, I spent the last quarter of the film unsuccessfully choking back the latter along with much of the audience.

But the film doesn’t go for the easy answer. Beneath its Blue-state, sexually open-minded veneer lies a rather solid traditional-values core, striking a blow for family integrity, regardless of exactly who’s in the family. As loveable as Paul can be, with his kale and fresh peppers and motorcycle and even occasional wisdom, his presence shakes up the family too much. His indiscriminate, “let’s all get it on” attitude grants one of the moms, the self-doubting, existentially lost Jules, a reason to act out destructively against loved ones and self. She transgresses her relationships and subverts her own sexual identity by sleeping with Paul, who happens to be the biological father of her children. This isn’t the kind of affair that’s brushed aside by an accepting clan. It devastates them. Ultimately, Paul’s supposedly freethinking, but really self-serving vision of his new role in the group must be pushed aside to preserve the old-fashioned family core, with its same-sex twist.

“Here’s to an unconventional family,” says Paul, during dinner, and he is heartily joined in a toast by all the characters. And yet it’s Nic, the cuckolded wife, who has the symbolic last word in the film, when she angrily calls Paul an interloper and slams the door in his face. “This is my family,” she says. “It’s not your family.” The boundaries of a family, Nic’s words indicate, are erected by far more than biology and even love. Work and commitment forge them.

Thus, the film puts itself forward as a classically-imagined adultery and family drama film that just happens to be about lesbians, and perhaps that may be the most radical thing about it, the way it builds on a normative, old-school scaffolding to make its point. Just as Brokeback Mountain used the conventions of the timeless, scenery-drenched, star-crossed love story to elevate its gay cowboys into American hearts and souls, The Kids Are All Right has us rooting to get that straight biological dad outta there and let the lesbians raise their kids already. It does this even as it humanely shows us the tragic side of Paul, an emotional drifter, suddenly discovering the fact that he does have the capacity to love deeply, lastingly. Although the conflict is resolved justly, Cholodenko and the actors allow us to feel for Paul as well as for Jules and for Nic, who are all hurting each other.

As to whether a gay woman would conceivably have a mid-life crisis by sleeping–enthusiastically and repeatedly so–with a straight man, it’s not impossible. There have been complaints that this twist gives credence to the errant belief that sexuality is a lifestyle choice, although Cholodenko makes pains to show it’s not. “I’m gay,” an irritated Jules tells her lover Paul when he suggests they become a couple themselves. Early on, we learn that “the Moms” enjoy gay, not lesbian porn, because it’s “externalized,” as Jules explains to her rather horrified teenage son. This scene serves to foreshadow her mistake, and illustrate the point that sexuality is fluid and spectrum-like and complex.

Yes, we all know that “straight” people have gay relationships and the inverse.  Still, I encountered the hurdle of motivation and believability when the Jules-Paul canoodling kept going. I definitely believed that Jules would get involved with Paul emotionally and perhaps sexually, but I didn’t fully buy that the affair would have such a continually sexual dimension to the exclusion of the psychological alienation that, I think Cholodenko believes, is the true threat to Jules’ marriage with Nic. And yes, it irked me very slightly that the gay sex, while definitely present and explicit, was played mostly for laughs under the bedclothes while the hetero sex was so cheerily, unabashedly out in the open (albeit concealed in key areas by bedposts and couch backs).

But this is a mainstream movie in its conception, even with its indie cred, and so marital conflict will be crystallized into an affair. It’s still noteworthy that this story’s victories, social and aesthetic, far outnumber its setbacks. Good acting has done a lot for various human rights movements in our country, and gay rights are the latest to receive the advocacy that is Hollywood’s talent: from Heath Ledger’s heartbreaking performance in Brokeback to Sean Penn and James Franco in Milk to this: Julianne Moore and Annette Bening giving two of the most heartbreaking, absorbing, and tour de force performances I’ve seen from either of them, with the rest of the cast matching their efforts admirably.

The film hits the target in one last respect, its treatment of teens. Like this spring’s female-directed Please Give, The Kids Are All Right gives us an achingly accurate portrait of the hell of adolescence, from Joni’s repressed perfectionism to Laser’s aping of a crude, toxic buddy. And yet the film’s title, and many moments throughout, serve to remind us that despite their naivete and inexperience, teens have a wisdom that can pierce through the BS and self-delusions of grown-up life, and attention must be paid to them, as indeed it must to this exquisite film.