SPOILER ALERT: This review contains spoilers for the nearly plotless musical film Mamma Mia!

It's almost unfathomable to those casually acquainted with Mamma Mia!, the ABBA musical, that a staunchly feminist heart might beat beneath its 70s-kitsch exterior. In fact, I used to mock the women who slavishly lined up for tickets to the Broadway musical, convinced that they were spending money on something commercial and contrived.

But then last weekend, when the weather was hot and I'd already been mildly traumatized by Batman: The Dark Knight, I stepped into the nearest theater and was wowed by the most feminist mainstream movie I've seen in ages -- it trumped Sex in the City, for sure. Mamma Mia! might not be about feminism, or seek to advance feminism, but it takes many of feminism's principles as a given, and works (or works it, if you will) from there.

The movie is ostensibly about a young woman, Sophie, who lives on a Greek island with her mother, an aging hippie and former pop singer. She invites three of her mother's former lovers to her wedding, hoping she'll figure out which of them is her father so he can give her away. Her mother Donna, played to the hilt by Meryl Streep, is an unabashedly sexy overall-clad woman whose surprise encounter with her former flames proves to reinvigorate more than just her memories.

It's a thinly-constructed story, mostly an excuse for the characters to jump around and sing ABBA songs with joyful abandon. But Mamma Mia! is also a movie in which female sexuality is celebrated without its objectification or punishment for its protagonists, and female sexuality is presented from young womanhood all the way through middle age and beyond.

The women express their sexuality through mildly raunchy dancing and jokes, a pleasant departure from the screen-archetype of the sensual female defined by languorous pouting and seduction. Some viewers have wondered whether it's problematic to see the actresses acting "vulgar;" but away from patriarchal norms, actual women are not demure and coquettish, but just as funny, silly, and randy as their male counterparts. And the tousled gorgeousness of Streep and Amanda Seyfried, who plays Sophie, promotes an outdoorsy, natural kind of sexiness at all ages that is a welcome contrast with SATC's urban fashionistas.

Furthermore, the movie's central premise -- a wedding between two young people -- never comes to fruition. At the end of the film, Sophie, unmarried, leaves with her fiancé to travel the world, rejecting the idea of settling down too early. Donna, as an afterthought, ties the knot instead with one of her old loves, after shocking the local priest with the revelation of her sexual exploits during the year of her daughter's conception. Then Sophie declares she doesn't care about said exploits, because she has grown to love all three men.

Presumably, none of the men care either, as they agree to share fatherly duties and turn themselves into one, big, irregularly-shaped but affectionate family. It's this conclusion that "love makes a family" that led film critic Dana Stevens to declare of Mama Mia!: it's "a transgenerational, pansexual paradise that's so deeply queer that when one of the characters comes out of the closet late in the movie, the revelation seems superfluous."

And incidentally, instead of having one of her three dads give her away at the outset of her abandoned nuptials, Sophie walks down the aisle with her mother by her side.

It's hard to imagine a movie that's come out recently that is, at its core, as offensive to the right wing's so-called family values. The film's women -- including a mother and daughter -- accept each other as sexual beings. Donna isn't punished for her earlier promiscuity, and Amanda isn't forced to get married despite her clear sexual maturity. The concept of three men revolving around a matriarchal family core is celebrated.

Admittedly, there are many feminists out there who will never love, as Stevens says, a "sunny, goofy gynotopia" as a vehicle for feminist values. And it's likely that a lot of Mamma Mia!'s audience probably doesn't identify as feminists -- they identify instead with the female-centric joie de vivre of the musical. But this is okay. In its way, the movie may reach more people as a stealth advocate of sexual egalitarianism -- which could be just what its nearly all-female team of production, writing and direction (a Hollywood rarity) had in mind.

The movie, seen so close in proximity to the more acclaimed Batman flick, did have me thinking about the part gender plays in what we determine to be serious. While The Dark Knight dealt with themes of power and violence, Mamma Mia! was about the more domestic, but no less universal, themes of family and forgiveness -- but both films were primarily interested in showy visual sequences. Critics slobbered all over themselves heaping praise on the former, while many admitted being embarrassed by Mamma Mia! The contrast between the way the two have been received makes one wonder why, to start with, we consider singing and dancing showpieces to be "silly" while Batpods, metal suits, and improbably-rigged explosives are allowed be taken quite seriously. We're quick to forgive the tokenization of female characters as villain-bait in superhero movies, but critics whine when men in movies like Mama Mia! and Sex in the City are relegated to love interest status.