“Adult Beginners” started life as a showcase for comic writer-actor Nick Kroll, who concocted the story. But any notion that the star of “Kroll Show” might reinvent himself with this film goes out the window when first we meet Jake, a fast-talking entrepreneur who has hustled every friend he has, and then some, into investing in “Mind’s I,” a Google Glass knockoff that failed.
Jake is just another version of Kroll’s recurring character on TV’s “Parks & Recreation,” whose nickname is a feminine hygeine product.
He’s self-absorbed enough to think fleeing to visit his pregnant, mother-of-a-toddler sister (Rose Byrne) unannounced won’t be an inconvenience.
“I need you to make me feel better,” a Summer’s Eve-by-any-other-name whines.
Since he’s broke, his too-understanding brother-in-law (Bobby Cannavale, playing another contractor) suggests he and Justine hire Jake a babysitter — their “manny” nanny.
So make way for the potty chair jokes, the hyperactive “devil child” wisecracks, substituting a suitcase with wheels when you can’t figure out how to work the stroller and flirt-with-the-other-nanny-in-the-park (Paula Garces) scenes as this narcissist figures out it’s not all about him.
Kroll is fitfully amusing, and packaged with Joel McHale as his best “bro” and mirror image in the city is good for laughs. But what works best is the extended family dynamic. Byrne and Kroll have a nice estranged sibling chemistry, not up to “The Skeleton Twins,” but in that ballpark.
Where are his glasses? She hasn’t seen Jake in years.
“Lasik.”
“Your eyes look kind of buggy.”
“Yeah, that’s the look I was going for.”
The second act complications are predictable, the third act revelations mild. Director Ross Katz, a producer with a couple of Sofia Coppola pictures, including “Lost in Translation,” in his credits, does little to disguise just how on the nose this script is.
But Kroll knows how to make bug-eyed feminine hygeine product characters funny, and since Byrne, Cannavale, Garces and McHale accept that about him, so do we.

MPAA Rating: R for language and some drug use.

Cast: Rose Byrne, Nick Kroll, Bobby Cannavale, Paula Garces, Joel McHale
Credits: Directed by Ross Katz, written by Jeff Cox and Liz Flahive. A Radius/TWC release.

Running time: 1:30