For some reason, the film's original title was Cruel Inventions, as revealed by Gellar on Instagram in a Throwback Thursday post.
"#throwbackthursday ok one last one because I was feeling nostalgic - and yes #CruelInventions was the original title," she wrote. "This pic was 1998 at our kick off dinner #cruelintentions #Crueltv#kathrynmerteuil."
And while the film was clearly a modern retelling of Les Liaisons dangereuses, Kumble also drew inspiration from another source.
"There was this movie called Welcome to the Dollhouse that Todd Solondz did," he told the Telegraph. "I loved that movie and I loved the fact that he was capturing mean teenagers, and I'd never seen it done that way."
Part of the reason Phillippe and Gellar ended up snagging their roles in Cruel Intentions was because of their work in the 1997 horror hit I Know What You Did Last Summer thanks to the two film's making the same producer, Neal Moritz.
"He was like, 'I just made this movie, I Know What You Did Last Summer, and there are these two actors in it; you really should meet them.' And it was Ryan Phillippe and Sarah Michelle Gellar," Kumble revealed to Cosmo. "And they were great. And I was just excited to get my movie made, so I was like, 'Great!' Once we cast Sarah and Ryan, then it got heat; we had two hot actors."
One of Hollywood's hottest blondes thanks to her star-making turn on Buffy the Vampire Slayer, Gellar wanted to separate herself from the popular WB series when it came to the seductive and devious Kathryn.
"That was Sarah's thing: 'I don't want to look like Buffy'" Kumble recalled.
But it was more than just the hair change that helped Gellar, who grew up on the Upper East Side herself, deliver such a stellar performance, as she really was able to embrace the debauchery of the character without wanting to make her sympathetic.
"We had long talks about her history. Roger used to always say, ‘Don't you think that she was abused?'" she told Premiere magazine in 1999. "And I'd say, 'No, I think she had a perfect upbringing. I think her mother adored her and her father sent her amazing gifts. She just wanted more."
Looking back on the experience, Gellar revealed to The Huffington Post that Cruel Intentions was one of her two "best film experiences," explaining, "We just knew we were making something that was so different and we were all so passionate and so excited. And we were all friends! It was just such a great time making that and letting it go as far as it did."
There was one aspect of playing the "Marcia f--king Brady of the Upper East Side" that Gellar did not love: "Although, the ground-up chamomile, the substitute I used for coke was not fun. I have allergies and since chamomile is kind of pollen-like, my nose and throat had it rough for a while."
Before casting Phillippe in the role, Kumble had his eye on another up and coming young actor.
"I was also looking at Jonathan Rhys Meyers at the time, because a lot of young Hollywood back then wanted to do it," he told The Telegraph. "Ryan just had that kind of Valmont air about him."
The Irish actor would go on to star in Bend It Like Beckham, Match Point and Mission: Impossible III, as well as eventually co-star opposite Witherspoon in Vanity Fair.
While Witherspoon snagged the role of good girl Annette, TV's favorite girl next door Katie Holmes was up for the part.
"This was early Katie, and I thought we needed someone with a little more strength of character," Kumble said of ultimately passing on the Dawson's Creek star.
Another name up for the part was Hocus Pocus' Vinessa Shaw, but the studio reportedly said no.
And then, of course, he wanted Witherspoon, going through her then-boyfriend Phillippe to snag her. "Literally, I was hanging out with Ryan one night and I was like, 'What about your girlfriend?'"
Kumble and Phillippe teamed up to convince Witherspoon, then 22 and known for her work in Fear and Pleasantville, to play Annette.
"So, basically, we took Reese out to dinner to get her drunk, and we ended up getting drunk. And I literally got down on my knees and begged her: 'Please, it'll be 15 days, you'll be great,'" Kumble recalled to Cosmo. "And Reese was like, 'I'll do it. But we need to work on the character.'"
And even back then Witherspoon, who has become one of Hollywood's most vocal supporters of Time's Up, was all about female empowerment.
"She wanted to strengthen the character, and she was right," Kumble said. "And she and I got together, and we gave Annette more bite so she wasn't a doormat. And I'm very grateful to her for that."
Witherspoon wasn't the only person that had to be talked into signing on to Cruel Intentions, as The Good Fight's Christine Baranski revealed she initially wanted to pass on the role of Cecile's uptight mother, Bunny Caldwell. Once again, Kumble resorted to begging.
"I had to be talked into doing that one," she admitted to the LA Times. "It was going to be shot during my first year's hiatus from Cybill and I was anxious to go home and be with my kids. The director begged and begged me and said, 'It's only a few scenes.'
It ended up paying off, as she continued, "I'm still making residual money off Cruel Intentions. It might be the movie that's made me the most in residuals because it is such a hit. I didn't do much in that movie and yet people will come up to me and quote my lines."
Back in 1999, Gellar and Blair's onscreen kiss was a big deal. And it won the award for Best Kiss at the 2000 MTV Movie Awards, with the pals recreating the kiss on stage.
Not in the script? That iconic string of spit that follows their kissing lesson. "I forget who, but someone said, 'We need to go again, there's saliva connecting them.' And [cinematographer] Theo [van de Sande] was like, 'No, it's beautiful.' And I was like, 'No, it's hot. I mean, we'll go again, but I think it's cool,'" Kumble recalled to Cosmo. "So it was a happy accident. And it's kind of been remembered for that."
When it came to actually filming it, Gellar once said, "Selma was afraid she would suck at kissing me. But she didn't!"
Blair (who was actually 27 playing the 15-year-old freshman Cecile) admitted to some initial nerves, but revealed Gellar had some too, saying, "Besides kissing my sister years ago in a game of truth or dare, I had never kissed a girl up to the point where I had to kiss Sarah. We shot our kissing scene on the last day of filming. And, it actually felt great. On our way from LA to NYC to film the scene in Central Park, I said to Sarah, 'Tomorrow we get to make out!' She was like, 'Shhhh. Don't speak.'"
For Gellar, the kiss, which was performed in Central Park with hundreds of extras and photographers around, ended up making tabloid headlines the following week. "[We] saw headlines that said something like, 'Sarah spends a day in Central Park with a friend,'" Blair remembered. "I guess they all had their telescopic lenses ready that day."
How did Blair end up landing the role that would serve as her big break? By being just as bratty as her character.
"It was the smartest audition I've ever seen in my career. I remember Selma came in and I said, 'How old are you?' And she goes [in Cecile's bratty voice] 'How old are you?'" Kumble told Cosmo. "And she was so obnoxious and I couldn't get it out of my head. She came into the audition as the character and didn't show me that there was Selma; I said, 'This is the person.'"
Appearing in small-but-memorable roles in the film? Dawson's Creek star Joshua Jackson, ditching Pacey's khakis and sporting bleach blonde hair as Blaine Tuttle, Sebastian's gay partner-in-blackmail. Plus, Ugly Betty's Eric Mabius (the closeted football player he ends up blackmailing), and Tara Reid, taking on a good girl-wronged-by-Sebastian just before hitting it big later that same year with American Pie.
Another small role that was filled by someone who would go on to dominate headlines? Eventual star of The Bachelor Charlie O'Connell, Jerry O'Connell's younger brother, who plays Kathryn's boyfiend, Court Reynolds.
And fun fact: Before she began dating her eventual husband Freddie Prinze Jr., Gellar and Jerry O'Connell actually were a couple. They met on the set of Scream 2 prior to Cruel Intentions. "We did date afterwards," Jerry revealed to People. "Not during shooting. We would've never complicated work and pleasure relationships."
A serious couple in real-life, Phillippe and Witherspoon had a tough time shooting Sebastian and Annette's break-up. In fact, it felt so intense for the couple that Phillippe physically got sick.
"Reese and I had a fight scene where we had to say horrible things to each other for four straight hours. After it was all over, I went outside and literally threw up," Phillippe told The Morning Call. "It was so emotionally punishing for me."
But wasn't the only one struggling with the scene, as the infamous slap Annette delivered across Sebastian's face was unplanned.
"At one point I was improvising off-camera for Reese," he recalled, "I guess I said some pretty mean things, so she came over and slapped me. Roger loved it so much he incorporated it into the scene. So basically I got slapped around for a couple of hours."
Though most people think the former couple met on the set of Cruel Intentions, Phillippe and Witherspoon actually met when he crashed her 21st birthday party years prior.
"It was a pretty intense, emotional connection that happened between Reese and me," he said. "There's a definite balance there. Reese is a happy, light-hearted person, but she's also incredibly intelligent. I tend to be considerably darker. She keeps me from getting too dark and depressed and that's essential in a business that's based on uncertainty and insecurity."
Go back and watch the movie and you'll see the costume designer dressed each character with care. Annette's all-light wardrobe was supposed to be in stark contrast to Sebastian's all-black look.
"Her palette was softer and sweeter but confident," Denise Wingate told Dazed. "I remember we wanted her in all white in contrast to Ryan's all black, and when he gets hit by a car and sees her it's almost as if she is an angel."
As for Cecile, it was all UES prim and proper except from one key piece that served as a dark homage to a fairy tale.
"I remember at the last minute deciding to put Selma in a red hooded sweatshirt so when she is leaving to go see Sebastian she looked like a contemporary Little Red Riding Hood going to see the Big Bad Wolf," Wingate recalled. "A lot of subliminal things go into my selection of costumes that usually nobody notices."
Spoiler alert: Sebastian still dies! Just in a slightly different way.
In an alternate version of the film's dramatic ending, Sebastian is still hit by a car, but not because he is protecting Annette from being hit. Instead, he just stops fighting Ronald (Sean Patrick Thomas) when he sees her approaching and gets unexpectedly hit by a vehicle when going to cross the street to talk to her.
The highest paid person on the film? The Rolling Stones. Why? As it turns out The Verve's "Bittersweet Symphony," which is forever tied to Cruel Intentions, wasn't actually the band's to release the rights to.
"That was another example of me writing a scene perfectly to music without getting the rights," Kumble told ABC News. "That was a nightmare… So we're like, 'Oh, let's get the rights from The Verve.' But then you find out The Verve doesn't own the rights, The Rolling Stones own the rights."
"So it was a headache," he continued. "It was one of those things where the studio was like, 'Try another song.' And we kept trying and trying and no one could agree," he continued. "And the studio was like, 'Let's just pay for it.' We paid for everything, but we really paid for that one."
Fortunately, it was money well spent.
One of the most iconic offerings from the '90s soundtrack the film boasted had to be The Counting Crows' "Colorblind," which is the song Sebastian and Annette's love scene is set to.
However, the filmmakers initially had a completely different song in place.
"For that scene, there was this Smashing Pumpkins song called 'To Sheila,' which fit perfectly. If you turn off the Counting Crows and play the scene to 'To Sheila,' it actually works quite nicely. And [it seemed like] we were getting the song, it was great," Kumble told Cosmo. "Billy Corgan was watching the movie. It was down to the wire, and then they give me the call: 'Smashing Pumpkins said no.' And we were like, 'Oh, f--k.' Because we were all in agreement then—the producers, the studio, and I: This is the right song."
While there was a debate over which song to pick...until The Counting Crows' lead singer Adam Duritz saw the film and inspiration immediately struck.
"The music supervisor came in and said, 'Adam Duritz saw the movie and loved it and he wrote this song and they're recording it tonight or tomorrow night, but here's a demo of it.' And we heard the opening, the piano, and we were like, 'Oh my god, this is great. We love this,'" Kumble said. "And Neal and I, we went to Adam's house, or the Crows' house they were renting at the time...and watched them record 'Colorblind.' We put it on the film and it was great."
Once one of young Hollywood's hottest couples, Phillippe and Witherspoon went their separate ways in 2007 after eight years of marriage.
Looking back on their split, Phillippe took the blame, saying, "I think more of the problem was age. When we got together we were so young I think it can create issues with two people in this industry because there's so much noise that goes along with it."
After welcoming their daughter Ava in 1999, three months after getting married, and son Deacon in 2003, Witherspoon said she "would never change anything," but talked about settling down at such a young age in a 2017 ITV interview.
"I got married when I was 23 and I had two kids by the time I was 27. So I don't know, you know, sometimes it's good to know yourself," the Big Little Lies star shared. "I would never change anything. I've said to my daughter, I think, you know, [at] 25, you start to know yourself a little bit better."
In 2011, the Oscar winner married Hollywood power agent Jim Toth, and have 10-year-old son, Tennessee, together.