Everybody’s talking about the bottle scene.

In a Sundance Film Festival where we’ve had a gymnastic sex scene (“The Bronze”) and a James Marsden-Jack Black coupling (“The D Train”), the raunchy scene that seems to be topping them all is in Leslye Headland’s “Sleeping With Other People.”

Jason Sudeikis plays a serial womanizer who befriends the woman he lost his virginity to in college (Alison Brie), now so paralyzed by her romantic obsession with a married man (Adam Scott at his most punchable) that she can’t have good sex with anyone else, even herself. So, using an empty green tea bottle as a prop, Sudeikis’ character takes it upon himself to show her some good female self-pleasure techniques, including something called the “Dirty DJ” that has to be seen to be believed.

“After we did it a few times, it started to become very sweet and romantic,” Brie said during the Q&A following Sunday’s screening of the film at the Sundance Film Festival.

“And educational.”

It’s a gotta-see-it scene in a film that it’s ikely a lot of people will see. While writer-director Leslye Headland’s last film, the cheerfully bilious “Bachelorette,” mostly got a video-on-demand release, “People” has the star power, the humor and the sweetness to be a big breakout hit.

After meeting in college, Jake (Sudeikis) and Lainey (Alison Brie) don’t see each other for a dozen years before running to each other at a sex-addict meeting. They opt for friendship rather than sex, and the chemistry between Sudeikis and Brie is very strong, Headland giving them lots of good, honest, often frank dialogue to lob back and forth. There’s also a ton of movie references throughout the movie, especially “The Graduate” and “When Harry Met Sally” but also “The Third Man” and “The Shining.”

Headland does a good job balancing the raunchy and the sweet, and the film is just littered with good comic actors, including Jason Mantzoukas, Amanda Peet, Natasha Lyonne, Andrea Savage, Billy Eichner and more. It probably adheres a little too closely to a romantic-comedy formula — it hits a perfect, bittersweet ending, and then plows right on through it for another 15 minutes to the ending we all know is coming.

Headland started out as a playwright, and said that in her early days was mortified that audiences would chuckle at plays that she thought were the next “Glengarry Glen Ross.” Eventually, she learned that she was on the right track by trying to be honest rather than funny.

“In comedy, you don’t write jokes, you write people,” she said. And bottles.