Dan Stevens and Rebecca Hall star in "Permission."

From Klaus Kinski trying to drag a steamship over a mountain in “Fitzcarraldo” to a giant ape being kidnapped and brought into Manhattan in “King Kong,” some of the best movies rely on some really dumb decisions.

So it goes in writer-director Brian Crano’s “Permission,” a charming and meaty romantic comedy-drama in which a seemingly perfect couple decide to jeopardize that perfection. Bad idea. “Permission” has a one-night-only screening in Madison at 7:30 p.m. Wednesday at New Vision Fitchburg 18, and will be on video-on-demand starting on Friday.

Rebecca Hall and Dan Stevens play Anna and Will, a devoted, insufferably cute New York couple who have been dating since college. They have a nice, safe, cozy relationship, the kind where they have pretty good sex and then immediately hunt for the TV remote afterward.

Their boringly perfect life bugs one of their best friends, Reece (Morgan Spector), especially when he learns that Anna and Will have never been with anybody else. How could they truly know they’re with the right one, he goads them, if they’ve never spent any time in a relationship with the wrong one?

Secure that nothing can threaten their romantic bliss, Anna and Will decide to experiment with seeing other people, just to see what it’s like. Anna meets a hunky musician (Francois Arnaud) in a bar while Will, more reluctant to stray, dallies with one of his clients, a rich and bored divorced woman (Gina Gershon).

At first, the couple treat sex outside the relationship as a sort of adventure, coming home the next morning to share stories of their escapades. Just when it seems like they might be able to make an open relationship work, things go bad. The couple aren’t prepared for the emotional blowback that comes from these extracurricular activities, especially when they move beyond just sex with these other people and start having real feelings for them.

“Permission” also follows a parallel storyline involving Reece, who is married to Anna’s brother Hale (David Joseph Craig). Hale wants to adopt kids, and spends his afternoons hanging out with a stay-at-home dad (Jason Sudeikis) at the dog park. Reece doesn’t want to discuss kids. At first, Reece and Hale’s problems feel like a distraction from the main storyline, but their situation eventually resonates as another take on the film’s main theme, of how even a pretty good monogamous relationship can stifle an individual’s needs.

Crano’s screenplay navigates these tricky waters with insight and empathy for everybody on screen, while refusing to offer anyone an easy out. Stevens and Hall are excellent, pushing these two very likable people toward some rather unlikable behavior without losing our affection. Hall, in particular, can convey all the conflicting emotions within Anna with a sad twist to her smile. Arnaud is effective as the lovelorn musician, but Gershon really shines, bringing depth and vulnerability to what could have been a one-note stereotype.

Unlike most rom-coms, “Permission” isn’t overly concerned with making sure all the characters pair up by the end of the movie into a happily ever after. Sometimes, the movie suggests, being alone isn’t such a bad thing if it helps you understand what you want in life. For what it’s worth, though, the film isn’t totally down on monogamy — not only are Crano and Craig married in real life, but so are Hall and Spector.

Rob Thomas is the features editor and social media editor for the Capital Times, as well as its film critic. He joined the Cap Times in 1999 and has written about movies, music, food and books.