In “That Awkward Moment,” starring Zac Efron and Imogen Poots, three guys vow to maintain their single status for as long as possible to support a friend devastated by a recent breakup. The plan gets derailed when they each fall in love and have to secretly work around their pledge to bachelorhood.

“So” is how “That Awkward Moment” begins every “awkward moment.” As in “So, what are we doing here?” Or “So, where do you see this relationship going?”

That’s the dating man’s lesson of “That Awkward Moment,” that “For girls, nothing good ever comes after ‘So.’” It’s a chatty romantic comedy in the modern mode — rude, nude and crude — with some funny, writerly riffs on relationships and how to avoid them.

There are laughs, in the lead couple’s “meet cute” moment in a bar, when she (Imogen Poots) trots out that fortune-telling trick common to sex-obsessed sitcoms: rebuffing a suitor by forecasting an entire failed relationship based on how a guy is dressed, the manner of his approach and his lame pick-up line.

But the movie, like star Zac Efron and writer-director Tom Gormican, never lets us forget that it’s trying too hard, straining to spit out sexy, silly patter, reaching for that raunchy costume failure at a dinner party, grasping for gross takes on trips to the toilet.

Efron, Miles Teller (“The Spectacular Now”) and Michael B. Jordan (“Fruitvale Station”) play three New York pals who vow, when the doctor of the trio (played by Jordan) is dumped by his wife, to stay single and enjoy the mingling. Together, they will build “a roster” of booty calls. And the moment a woman starts “the talk” with “So,” they’ll bail. That’s the plan.

Which all of them ignore. Jason (Efron), a smart-aleck designer of book covers, falls for this cute one-night-stand, Ellie (Poots), who works for a publishing house. The hilarious chatterbox Daniel (Teller) starts to realize that his gorgeous, able-bodied lady wingman (Mackenzie Davis) is all the woman he’d ever need. And Mikey (Jordan) clings to the hope that his cheating lawyer wife (Jessica Lucas) will hear his reasoned, “We checked off all the boxes” appeal to maintain their partnership masquerading as a marriage.

“That Awkward Moment” is a writer’s comedy, and it’s easy to see why this cast was drawn to Gormican’s script. It’s a less emotional, less consequential updating of “About Last Night,” the David Mamet play (“Sexual Perversity in Chicago”)-turned-movie which, coincidentally, has earned an urban/African-American remake this Valentine’s Day. The quips and riffs are sharp and sometimes spot-on.

Efron never quite holds his own with the much funnier Teller, whose swagger and confidence always seem to be compensating for his awareness that he’s nobody’s idea of a hunk.

The quirkiest “awkward moments” in the picture come from Josh Pais, as the pathologically shy and clumsy boss who reintroduces himself to his creative team (Jason and Daniel) every time he meets them: “Hi, it’s Fred.” Squirm-inducing and funny. The rest of “That Awkward Moment” isn’t awkward at all. It’s overfamiliar, a movie that plays like recycled, R-rated outtakes from “Rules of Engagement” or “How I Met Your Mother.”