• Courtesy of Dominic Spillane
• Maren Langdon Spillane and Kianna Bromley perform in 'Cry It Out' by Dirt Road Theater in Northfield

A new mother has many decisions to make, including how best to extract snot from a baby's nose. For some choices, all you get are ways to be wrong, because staying home versus going back to work is the ultimate lose-lose decision. In Molly Smith Metzler's sparkling comedy Cry It Out, we meet four new parents with nothing in common but infants keeping them up at night. The Dirt Road Theater production brings out the humor with impressive ensemble acting, while the script reveals some unglamorous and very funny truths about motherhood.

The 2017 play is set in Port Washington on Long Island, N.Y., a suburb of extreme socioeconomic diversity. In seven short scenes, three new moms and one new dad — varying in affluence, demeanor and goals — convey the comedy of days that are ruled by nap schedules, breastfeeding and living in leggings.

When Lina (Kianna Bromley) takes up an invitation from next-door neighbor Jessie (Maren Langdon Spillane) to meet for backyard coffee, they seem unlikely to form a friendship. Lina's chunky South Shore accent, glowing press-on nails and not-ready-to-marry boyfriend all suggest that she has little in common with Jessie, a corporate attorney with a conscientious husband who shares his parents' pride in status displayed through real estate.

But Lina and Jessie's differences fall away in the face of their common experience keeping their firstborns fed and diapered while in virtual exile from the regular world. After being cooped up with babies whose conversation doesn't extend past burping, the women suddenly have the freedom to reveal the post-pregnancy aches, doubts and indignities they don't dare express to anyone who hasn't shared them.

While their newborns nap, they drink coffee in Jessie's backyard at the sweet spot where both their baby monitors are in range. As their friendship deepens, they can laugh through disagreements. Soon they're influencing each other. The genteel Jessie is considering sleep training, in which babies are left alone to cry it out until they sleep. The hard-edged Lina counters, "You put your baby down in a dark crib and let them scream until they learn no one's coming for them? I mean, are we Vikings?"

Each mother faces the big problem of when to return to work. Jessie is on the partnership track in her law firm, and her husband wants her second income back. But after a difficult birth in which she nearly lost her child, Jessie doesn't want to leave her. Lina's finances force her to go back to work, even though her only day care option is her day-drinking mother.

Metzler skillfully shows the influence of class on parenting choices and the blunt impact of the extent of economic resources. Many doors are closed for Lina; almost everything is open to Jessie. Still, they both want to choose from their hearts, not their wallets.

One of Port Washington's wealthiest enclaves overlooks Jessie and Lina's street. After observing the two of them, literally from on high, Mitchell (Jesse Cooper) impulsively visits during one of their coffee dates. Mitchell thinks his wife, Adrienne (Sarah Debouter), is struggling as a new mother and needs friends like them. Will they invite her in?

They try, but Adrienne faces challenges tougher than theirs. The playwright makes a commendable effort to go beyond the superficially laughable woes of motherhood and consider the darker side, where real desolation lies for a new mom without a physical and emotional bond to her baby. But the shift in tone is abrupt. It's as if Joey and Chandler of "Friends" had to shut down their routine hilarity when they found themselves sharing the coffeehouse couch with a burn victim.

Structurally, Metzler spends little time establishing Adrienne's objectives or addressing the equally nuanced question of Mitchell's preference for parenting over corporate life. Cry It Out presents four characters to embody the range of forces affecting new parents, but only Lina and Jessie get to share enough repartee to make their choices matter to the audience.

Director Joanne Greenberg, so adept at firing up the humor and finish-each-other's-sentences connection between Jessie and Lina, can't rescue the underwritten Adrienne and Mitchell. Adrienne's sullen presence doesn't spark a viewer's curiosity about her burdens — she's withdrawn but never missed. Mitchell is portrayed as either sweetly concerned or intrusively critical of his wife, and the playwright's ambiguity stays confusing.

What Greenberg does best is set a tone of unaffected intimacy to catapult Lina and Jessie into each other's lives. Their friendship chemistry gives the production a thrilling life force, especially because it transcends the boundaries of class and temperament.

In movement and attitude, Langdon Spillane gives Jessie a certain uptight precision, primed for Lina to dismantle. We know Lina is having an effect when Jessie follows her own outburst by protesting, "I don't curse in real life." Jessie is accustomed to meeting expectations, and Langdon Spillane conveys that stiffness with little hesitations before indulging in the raucous exchanges that Lina fosters.

Bromley is a comedy demon as Lina, stomp-walking to the backyard and flinging out her acerbic observations in a brutally working-class accent. Lina wins us over by being hardest on herself, and Bromley is a master of self-deprecation without self-pity. Lina's finances and family mean she faces difficulties Jessie never dreamed of, and Bromley summons her go-girl gumption with a loose, unselfconscious freedom.

Despite their thin characters, Cooper and Debouter both deliver solid and affecting performances.

The pinpoint wit of Cry It Out gleams in each line of dialogue. The play is a meditation on friendship, as well as a keen look at how parental choices now reflect economic opportunity more than emotional needs. Lina and Jessie are different in every dimension, even coffee preferences. But when they meet, they look only for what they can share. It makes them wonderful mothers, and wonderful to watch.

Updated on August 29, 2024: An earlier version of this story incorrectly listed the matinee dates for this play. Matinees are on Saturdays.