Night Eyes (“He watched her every move”), released in 1990, was a breakthrough erotic title. Andrew Stevens co-wrote and starred as a security guard who became enthralled with the married woman (Tanya Roberts) he was hired to spy on by her cheating husband.

The film was released by Prism Entertainment, which distributed all types of films—but it was to the direct-to-video erotic thriller what, say, MGM was to the Hollywood musical. “We knew what we had,” Prism founder and former CEO Barry Collier tells Vanity Fair. “They were intended to be filler. Nobody went into a video store in those days and asked for a Prism picture. They would ask, ‘Do you have Top Gun or The Princess Bride? If all of those were rented, they would ask for a recommendation. Twenty-thousand mom-and-pop video stores couldn’t fill their store with just ‘A’ titles.”

Night Eyes sold 25,000 copies and earned $1.2 million domestically. “It was a business model that worked,” Collier said. “We were able to recoup our negative costs and be into profit just on the home-video release. We still had pay cable and syndication in the States, and we owned the rights to those films throughout the world.”

And when Weber saw Basic Instinct in the theater, he anticipated customers would want even more products like it. “Of all the genres,” he said, “erotic thrillers rated at the top” in terms of rentals. “They skirted the edges, so there was a lot of titillation—[but] it was pretty harmless stuff. And (the actors) were nice people. If we brought one of them in for a special event or grand opening, they would pack the house. Forget about getting a parking place anywhere in the vicinity.”

Shannon Tweed in Scorned, 1994. From Universal/Everett Collection.

Really, what Basic Instinct did was cast the die and establish the formula for these films: “beautiful woman gets in trouble, is stalked, has a horrible boyfriend, is the target of some kind of sinister plot,. But through it all, she has time to take all of her clothes off and spend quite a bit of time making love to somebody,” Arnold explained.

When Basic Instinct hit, some savvy producers titled their erotic thrillers with suspiciously similar-sounding names to hook less-discriminating video store patrons. Also celebrating their 25th anniversaries this year are the voyeurism drama Animal Instincts (All you have to do . . . is watch), starring Shannon Whirry, and Fatal Instinct (Following your instincts can be murder)—not to be confused with Carl Reiner’s parody of the genre released a year later. The films flooded shelves, leading Blockbuster—which, as America’s family store, did not stock unrated movies—to create its own rating, 17+, and to establish the erotic thriller as its own genre section. “There was a point in time when we were a little on the staid side,” he said. “We did broaden our scope a little. But the erotic thriller was fun, and it was just titillation. We were always amused when the screeners would come in.” Executives would try to project how many times a title would rent based on how many nude scenes it contained.

Even legendary producer Roger Corman, who produced trend-setting sexploitation films for the drive-in market in the 1970s, got in on the act with two installments in the Body Chemistry franchise. Both were directed by Wynorski.

“The floodgates opened,” Wynorski recalls. “They were easy to make. It didn’t require any action. You could get them done well in 12 days. The trick was making them for low money. There was plenty of competition, so you had to be good and you had to get those big stars naked. Shannon Tweed, Andrew Stevens, Shannon Whirry, Tanya Roberts all started working double time.”

Tom Reilly and Shannon Whirry in Animal Instincts, 1992. From United Archives/Alamy.

“I was super, super busy,” recalls Tweed, who had done a lot of television work in the 1980s on shows ranging from Cagney & Lacy to L.A. Law. “I had two kids and a [boyfriend, Kiss front-man Gene Simmons] who was on the road cheating on me all the time. We weren’t married, and I needed to make my own nest egg. I was very conscious of being sure I worked as much as I could, because I knew the gravy train would end sooner or later.”