In a new interview with Vice's women's interest channel, Broadly, the couple opens up about how they single-handedly fashioned themselves into the reality show's villains and what exactly their life together has been like in the aftermath of that decision.
Spencer, 32, explains that after The Hills premiered in 2006, he became determined to join the cast and regularly hit up Hollywood nightclubs with Brody Jenner, trying to meet the stars of the MTV hit.
Soon enough, he met Heidi: "I pretty much told everyone I was going to marry him and that I loved him," Heidi, now 29, told Broadly. "[Everyone] thought I was crazy." (They ultimately did get married on the show in 2009.)
Eventually, in 2007, producers agreed to cast Spencer on the show. At the time, Heidi was billed as main star Lauren Conrad's sweet small-town sidekick from Colorado, but Spencer says he made it his mission to get Heidi from the B-plot to the A-plot: "Operation Upstage," or "Upstage LC," he called it.
Spencer explains he approached the show from the perspective of a producer because of his previous experience in 2005 executive-producing The Princes of Malibu, a short-lived Fox series about Brody and his brother Brandon Jenner.
"I didn't know how to be on-camera talent," he said.
Molly Matalon / Broadly
"Lauren had never been in a tabloid until I started calling the paparazzi on her, for her," he said. "[Lauren] is from Laguna Beach. I'm coming from L.A. All my friends' parents are producers and directors. I see the bigger vision of making content."
Meanwhile, according to Heidi, Conrad "didn't like someone coming in and changing up the formula because it was her world and she wanted it to stay that way."
Now, though, Heidi said she still has "such a soft part in my heart for Lauren."
"I love the time that we had together. I really do appreciate everything that she did for me. I wish that it had turned out differently," Heidi added.
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Meanwhile, the couple continued to capitalize on their fame by securing partnerships with photo agencies and selling paparazzi shots of themselves: "We were fame whores, getting literally a million plus a year in photos and being hated for it," Spencer said. "It's frustrating for me that people don't recognize that this was genius. This was innovating!"
Heidi and Spencer even claimed Kourtney Kardashian and Scott Disick based their own televised relationship on Speidi.
According to Heidi, Kardashian reached out to her sister, Holly, for advice: "She asked, 'What do Heidi and Spencer do? I need [to know] all the exact things, because we're doing exactly what they do,'" Heidi says.
Kardashian's publicist did not return Broadly's request for comment.
"To me, it's entertainment," Spencer said of their staged drama on the show. "If you grew up in Palisades, you think, This is fun! Whatever. You make up these stories! So I didn't get that you can get murdered in the press, literally. I thought it was like a comic book."
Eventually, the negative media attention started eating away at Heidi, and when a doctor approached her offering to give her 10 plastic surgery procedures worth $300,000, she agreed.
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Looking back now, Heidi admits she "was not in the right mind frame to make that decision."
"I was in so much pain," Heidi said of her six-month recovery. "I was literally crying every day."
"I became the character that I was pretending to be," Heidi continued. "I was pretending to be this Hollywood materialistic girl on The Hills that they kept telling me to play out, and I really started becoming more like that. Like you hear with actors, they need to take a break because they start becoming like the movie characters they've played. When you play pretend, you have to be really careful with that."
In 2010, MTV cancelled The Hills and scrapped plans that were in the works for a Speidi spin-off.
"[The Hills getting canceled] was our 9/11," Spencer said, explaining that they had saved none of their fortune.
Now the couple lives rent-free in Spencer's dad's beachside vacation home near Santa Barbara, California, and Spencer readily admits they don't actually need the high-tech laser security system they installed: "Nobody wants to break into our home anymore. They Google our new worth and see we are worth $10."
At the end of the day, though, all that really matters to Spencer and Heidi seems to be each other: "I love Heidi because she's the most special angel I have ever come across," Spencer said. "Heidi is like the sunset."
"No one has ever made me feel so good," Spencer added. "I never even thought it was possible to feel this good."
And as for Heidi? She wouldn't take back any of it, either: "The biggest misconception about us is that we wouldn't do it all over again," she said.
Update: On Friday, Spencer took to Twitter to apologize for making "such a thoughtless analogy" in reference to his 9/11 comment.
RE: my 9/11 comment: I want to apologize for making a such a thoughtless analogy. (1/5)— Spencer Pratt (@spencerpratt) February 19, 2016
I’m not going to make dumb celebrity excuses about being taken out of context. (2/5)— Spencer Pratt (@spencerpratt) February 19, 2016
I just said something dumb and potential hurtful to a lot of people and that’s all there is to it. (3/5)— Spencer Pratt (@spencerpratt) February 19, 2016
"I'm not going to make dumb celebrity excuses about being taken out of context. I just said something dumb and potential hurtful to a lot of people and that's all there is to it," he wrote. "I'll likely say something dumb again, but I know I need to check myself on this one. Again, apologies to anyone I offended and for being insensitive."