“You’ve gotta go with a Cheesy Gordita Crunch,” Dave Chernin says as he scrolls through the options on the digital kiosk at a Taco Bell Cantina in Chelsea. “I’m ordering one for you too,” he assures John Chernin , his older brother (by 15 months) and writing and directing partner.

The siblings are in New York City to promote “ Incoming ,” a high school comedy about four nerdy friends that’s a raunchy throwback to movies — like “Superbad” and “American Pie” — that topped the box office back before superhero flicks subsumed Hollywood. And yes, the Chernins know there’s more authentic Mexican food to be had in the neighborhood, but we’re thinking outside the bun as a tribute to an outrageous scene in their R-rated film. It’s one that finds two freshmen (Ramon Reed and Raphael Alejandro) taking an intoxicated older classmate (Loren Gray) on a chalupa run. Given that their fast-food excursion ends with explosive diarrhea and a Tesla interior in desperate need of deep cleaning, “Incoming” probably won’t be part of Taco Bell’s next ad campaign.

“The script called for Taco Bell,” Dave explains. “There was a lot of discussion about whether we could actually use the name. Made-up names like Taco Town just didn't seem as funny. So we got creative and avoided showing the wrappers or an actual Taco Bell restaurant.”

The scene, the brothers say, was inspired by a very real story — even if the names and the restaurant have been changed. In fact much of “Incoming,” which follows the kids as they try to get an invitation to a big party, draws on the house parties that Dave and John attended growing up. But when they sat down to write the movie, they worried that gravity bongs and beer kegs would seem, well, outdated.

“We spent a lot of time discussing whether kids even go to parties these days?” says John. “And then we thought about asking our friend’s teenage kids, but then that’s kind of awkward. You don’t really want to ask them in front of their parents.”

Since the Taco Bell is more crowded than the high school party that takes up the majority of “Incoming,” we relocate, lunch in hand, to nearby Madison Square Park. The brothers are carrying Modelo Especials with their bag of burritos, so there’s a flicker of concern about walking up 23rd Street with open containers of alcohol. “It will make the article more interesting if we get arrested,” John offers.

The Chernins, whose father is media mogul Peter Chernin, have collaborated throughout most of their careers, including stints writing on “It’s Always Sunny in Philadelphia” and creating “The Mick.” “We just have a shorthand together that goes back decades,” John says.

Despite the brothers’ comedic background, major studios weren’t interested in supporting “Incoming.” Instead, the film was produced independently by Spyglass Media Group and sold to Netflix after its completion. Part of the reason, the Chernins say, was that studios aren’t producing many R-rated comedies, and there’s greater sensitivity about humor that pushes boundaries and can go viral for the wrong reasons.

“We received a lot of feedback like ‘The script was hilarious, but it’s not really what we’re doing right now,’” says Dave. “There were some concerns about the children taking drugs,” adds John.

But working on “It’s Always Sunny,” a hugely popular show that has one foot in cringe comedy and the other firmly planted in dark humor, has helped the brothers learn how to walk the fine line between irreverent and mean-spirited.

“We’re not afraid to tackle those tricky situations,” Dave says. “‘Always Sunny’ is completely unafraid to go anywhere as long as it’s funny. That’s because there’s an unspoken understanding between the audience and the show's creators — the people making the show are on the right side of things, despite the awful things the characters do. We’re making fun, not celebrating them.”