Zendaya, clad in a skintight dress, gyrates on a dance floor in “Challengers,” a $56 million sports drama that arrived in multiplexes on Friday. “It’s getting hot in here,” the hip-hop soundtrack intones, as she closes her eyes and runs her hands through her hair, lost in fantasy. “So take off all your clothes.”

The story continues at a motel, where Zendaya, playing a tennis prodigy, begins a ménage à trois with two guys; it fizzles after they become more interested in each other. The plot moves on — to sultry interplay on the hood of a car, in a dorm room, in the back seat of a car, on the wooden slats of a sauna. There is erotic churro eating.

“Sex is back!” shouted an apparently elated man at the conclusion of a prerelease “Challengers” screening in West Hollywood, Calif., this month.

Trend spotting in cinema is a hazardous pursuit. Think about how many times the rom-com has been declared dead — and alive — and dead. (No, wait, alive.) But this much can be said with surety: Hollywood is hornier than it has been in years.

“It absolutely feels like the pendulum has swung back toward filmmakers exploring adult relationships and sexuality in their projects,” said Amy Pascal, the former chairwoman of Sony Pictures and producing force behind “Challengers.”

“I welcome that,” she added.

Eroticism used to be common in studio movies like “Challengers,” which was released by Metro-Goldwyn-Mayer. “Body Heat,” “Basic Instinct,” “An Officer and a Gentleman,” “Fatal Attraction,” “Disclosure,” “Cruel Intentions” and “Eyes Wide Shut” are among the many examples from the 1980s and ’90s.

In the 2000s, however, film companies started to obsessively focus on PG-13 franchises and animation — genres that could play to a global audience and sell merchandise. Studios also wanted to expand into China, where censors do not allow sex scenes. As a result, steamy storytelling began to dwindle on the big screen (except at art house theaters). Premium television picked up the slack.

Sex in mainstream movies was “pretty much gone” by 2019, as Ann Hornaday, chief film critic for The Washington Post, wrote in a column that year. A few months later, Kate Hagen, writing in Playboy magazine, found that only about 1.2 percent of films released between 2010 and 2020 contained an overt sex scene, the lowest decade total since the 1960s. (It peaked in the 1990s. Coincidentally or not, that was the decade when pornography started to become available online.)

Now, some filmmakers are pushing back.

Awards season brought “Saltburn,” with its arousing-disturbing bathtub scene and Barry Keoghan’s twirling, full-frontal finale. “Poor Things” found an insatiable Emma Stone romping through a Paris brothel. Christopher Nolan filmed the first sex scenes of his 35-year career for “Oppenheimer.” (“More interested in the joys of sex than any recent season I can remember,” as Kyle Buchanan, awards columnist for The New York Times, described the crop of contenders in February.)

Over the past year, the trickle of R-rated sex comedies in theaters turned into a relative torrent. “Anyone but You” found Sydney Sweeney and Glen Powell going at it. “No Hard Feelings” starred Jennifer Lawrence as a kinda-sorta prostitute on a mission to deflower an awkward student. The libidinous “Bottoms,” “Back on the Strip” and “Joy Ride” also tried mixing sex with laughs.

In late May, Mr. Powell will return to theaters in the comedic “Hit Man,” about an undercover agent who begins a smoking-hot affair with a suspect, played by Adria Arjona. In addition to acting in the R-rated film, he co-wrote the screenplay with Richard Linklater and served as a producer. (It will arrive on Netflix in June.)

“‘Body Heat’ was one of the inspirations,” Mr. Powell said in January, when “Hit Man” debuted to rave reviews at the Sundance Film Festival. “There aren’t many sex scenes in movies anymore, and certainly not many that are done well.”

He continued, “‘Body Heat’ has a lot of foreplay, which is one reason it feels so intense — steamy, carnal.” (“Body Heat,” released in 1981, starred Kathleen Turner as a wealthy woman who plots the murder of her husband while having a torrid affair with a sleazy lawyer, played by William Hurt.)

The multiplex lineup for this summer includes “Deadpool & Wolverine,” from Disney-owned Marvel Studios; a trailer included a joke about an intimate act involving a sex toy. (The activity “isn’t new for me,” Ryan Reynolds jokes as the mischievous Deadpool, “but it is for Disney.”) “Blink Twice,” a twisted thriller starring Channing Tatum as a mogul who lures women to a private retreat, is scheduled for release in August.

The upturn may simply be a scheduling quirk. “Challengers” was supposed to come out last year, but it was delayed because of union strikes. Its arrival now — sandwiched between “Poor Things” and “Hit Man” — could be creating the false appearance of a film industry turn.

But there are signs that suggest a genuine shift. One involves intimacy coordinators, or experts who help performers navigate the awkwardness of filming sex scenes. Their inclusion on sets, once a rarity, became common after the #MeToo movement of the late 2010s. Film producers say stars have become more willing to participate in simulated intimacy as a result.

Young screenwriters and directors also seem to be rediscovering movies like “American Gigolo” (1980) and “9½ Weeks” (1986) and drawing inspiration. Some studio executives say filmmakers like Luca Guadagnino, who directed “Challengers,” are interested in exploring changing attitudes about sex — as seen in the rise of OnlyFans and the shame-free embrace of sexual fluidity by younger millennials and Gen Z. (One counterpoint: In a study last year by the Center for Scholars & Storytellers at the University of California, Los Angeles, about 52 percent of respondents ages 13 to 24 said they wanted movies and TV shows to focus more on friendships and platonic relationships.)

Perhaps contributing a degree of sexual liberation: Studios have stopped chasing China, where ticket buyers have turned against Hollywood movies en masse.

So far, results at the box office have been mixed. “Anyone but You,” made by Sony for $25 million, collected a hefty $219 million this year, while “Poor Things,” which cost Searchlight Pictures $35 million, took in a solid $117 million. Other attempts (“Joy Ride,” “No Hard Feelings”) have disappointed or fizzled entirely.

Reviews for “Challengers” have been extremely positive. Box office analysts expect it to collect roughly $15 million in its debut weekend in the United States and Canada, where it is playing in 3,400 theaters, enough for No. 1.