There are a lot of reasons to like this pleasurable and occasionally steely portrait of a middle-class Los Angeles marriage facing a sexless “dry spell,” but by far the biggest is Kathryn Hahn, a frank, funny and immensely enjoyable comic actress who’s had recurring roles on “Girls” and “Parks and Recreation” (and is probably best known for playing Lily in 115 episodes of “Crossing Jordan”). Hahn’s never played the leading role in a film before – I suppose she’s the character-actress “type,” though she’s plenty attractive — and Soloway deserves a big wet smooch from the universe for giving her the chance. Rachel, the bored and unhappy housewife heroine of “Afternoon Delight,” is an immensely demanding role. She’s sardonic, self-deluded, passive-aggressive and deeply misguided, all without entirely losing our sympathy and while clad in a depresso wardrobe composed of castoff elements from the last three decades: a horrible sailboat-print sweater, a Peruvian alpaca poncho, pantyhose and a subtly unfashionable skirt.

Rachel is trapped in a weird, slightly hipsterized reboot of the 1950s: She’s at home with her young son while workaholic husband, Jeff (Josh Radnor of “How I Met Your Mother”), runs an “apps publisher.” But home is the pseudo-bohemian paradisiacal L.A. enclave of Silver Lake, rather than suburbia, and the convenient fiction is that Rachel is “trying to write” rather than simply not working. In many ways the best things about “Afternoon Delight” lie in Soloway’s merciless and highly specific depiction of creative-class Jewish life in L.A. There’s the nightmarish, hawk-nosed so-called friend (former “SNL” cast member Michaela Watkins, who’s now on “Enlightened”) who’s always badgering Rachel about running the hot-dog table at the JCC’s annual “Craftacular.” There’s the woman who is mocked as “Kosher Amanda” (Annie Mumolo) for being slightly more observant than the rest of the moms. There are Groupons, and yoga, and brunches, and fights over the best nannies.

Armed with half-baked advice from her best friend (Jessica St. Clair) and her lesbian therapist (the reliably hilarious Jane Lynch), Rachel and Jeff try to jump-start their sex life by visiting a strip club, where Rachel receives an awkward lap dance from a perky, frizzy-haired 19-year-old named McKenna (English actress Juno Temple, who is actually 24 but does a flawless California girl). Soloway never tries to define or explain exactly why Rachel becomes obsessed with McKenna, and I think that’s perfect; the story suggests various reasons, and they’re all correct. It isn’t entirely a same-sex crush, although that element’s in there; it isn’t just a fascination with McKenna’s up-front sexuality, though that plays a big role; and it’s only partly misplaced liberal do-gooderism, though that’s Rachel’s official excuse. (Only one of these two women is in a dire predicament and badly needs help, and here’s a hint: It’s not McKenna.) More than anything, it’s intense loneliness, along with the desire – as Rachel puts it later – to throw a bomb into the middle of her life.