The biggest curse of modern romantic comedies is that they can be too clean. No, I don’t mean the absence of rough language and nudity. I’m talking about how nice and tidy — and full of crap — rom-com screenplays can be when they follow the formula but leave out the authenticity.

Movies that deal with affairs of the heart should be messy. Relationships are messy. They are chock full of give and take. And fear; lots of fear. Attraction between two people is rarely mutual for extended periods — and never in equal measure. To make matters worse, people in love make boneheaded decisions on a regular basis.

In her first two films — 2012’s underrated “Bachelorette” and the fine new comedy “Sleeping with Other People,” now playing at Liberty Hall — writer/director Leslye Headland has proven she understands this. She has a knack for taking familiar rom-com situations and injecting into them a hardcore dose of truth. Truth can be uncomfortable, but as both of these movies illustrate, it can be riotously exhilarating as well.

Jason Sudeikis and Alison Brie are their usual charming selves in “Sleeping with Other People,” but they are also damaged goods. This isn’t one of those dumb movies where attractive people play nerdy and only “get sexy” once they get their confidence. No, Jake (Sudeikis) and Lainey (Brie) are already having a lot of sex — Jake with every girl in New York, and Lainey with a married doctor (Adam Scott) who keeps stringing her along.

Lainey’s obsession with the doctor isn’t just some cute subplot to create the eventual third-act breakup and reconciliation — it’s long-term, and downright dangerous, having held her back emotionally for her entire adult life.

Jake acknowledges that his swinger mentality may be a problem on some sort of deep level, but outwardly, he dismisses it with the same casual flirty tendency that he uses to lure women into bed.

For Sudeikis, this is a chance to augment his usual quick wit and comic timing with some darkness. It’s not a lack of commitment holding him back from a real connection — it’s an intense fear of his own worst tendencies.

For Brie, it’s a chance to ditch the bubbly character she played on “Community” and more fully explore the vulnerability she exhibited on “Mad Men.” It’s the highlight of both actors’ careers — and the chemistry that’s so important to rom-coms is here in spades.

Even more so than this summer’s breakout Amy Schumer hit “Trainwreck,” “Sleeping with Other People” isn’t afraid to spotlight the frailty and stupidity of its characters. Where Schumer’s moral compass follows a more traditional path to self-awareness, Headland’s characters’ self-destructive tendencies aren’t struck down — or explained away — so simply. Whatever’s special that Jake and Lainey have is hard-earned, and the movie is better for it.

‘The Martian’

For all of the plaudits Ridley Scott‘s space exploration drama “The Martian” has been receiving for its scientific accuracy, it should get at least as many for its avoidance of weepy melodrama.

Yes, astronaut Mark Watney (Matt Damon at his most Matt Damon-y) is stranded on Mars with no conceivable hope of rescue. Thanks to screenwriter Drew Goddard (adapting from Andy Weir‘s 2011 ebook), however, the movie becomes a briskly moving thriller about plucky American spirit, highlighted of course by a MacGyver-esque ability to solve any problem.

There’s no time for kissing photos of loved ones back home on Earth. Mark isn’t even married — and he doesn’t have kids either (how dare a Hollywood script leave that opportunity unexploited).

“The Martian” is an efficiently plotted story about a life-or-death crisis bringing out the best in people, and it’s a joy to see Scott operate in this arena after the lugubrious excess of “Exodus: Gods and Kings” and “The Counselor.”

If there’s one fault to find in this inspiring tale, it’s that Damon’s botanist/engineer is just too smart, generous and self-effacing to be a real human being. But to say that would be too cynical — a trait this film is hiding away in the same cupboard, thankfully, with all of the schmaltz.

‘Sicario’

On the 100 percent opposite side of the spectrum as “The Martian” lies a movie of astounding technical achievement with a heart even blacker and uglier than you may imagine the U.S./Mexico border-town drug wars to be.

“Sicario” stars a mysterious Benicio Del Toro and a cocky Josh Brolin as leaders of a U.S.-led anti-cartel task force that knows no moral boundaries. Emily Blunt is the audience’s stand-in as a tough special weapons FBI agent witnessing all kinds of brutality — on both sides — firsthand.

Director Denis Villeneuve is a master of mood. Dread permeates every moment of “Sicario,” and cinematographer Roger Deakins will likely net his 13th Oscar nomination for his gritty, agile work.

There’s not much emotional investment in any of the characters, and the film has little to add to any serious discussion of its subject matter — but as a pitch-black thriller, “Sicario” succeeds with style.