Paris Hilton Admits Her 'That's Hot' Catchphrase Was Actually Coined by Sister Nicky

"That's hot" became the unofficial catchphrase of the 2000s we thought was coined by Paris Hilton. Turns out, we've been living a lie.

The 38-year-old heiress and socialite just revealed that the two-word slogan she said in response to red carpet questions, uttered countless times on the "The Simple Life" and had printed on thousands of T-shirts was actually something her younger sister, Nicky Hilton, used to say.

We've been bamboozled.

"In 2000, I was a New York socialite," Hilton told Vogue in a video interview all about her obsession with Juicy Couture tracksuits. "I was modeling, I was doing my thing, I loved to go out. The 2000s were all about Britney Spears, boy bands, it was all about monogram and labels like Chanel and Dior and Louis Vuitton. I feel like everybody just had really fun with their fashion choices, so I think it was about being super extra."

"I've always been obsessed with wearing lots of pink and sparkles, a lot of Swarovski crystals," she went on. "I loved big chokers and anything that was bright and stood out. And then I started making shirts that said, 'That's hot,' and on the back would say, 'You're not.' It was cute. 'That's hot' is something that my sister actually always used to say, but I trademarked it and I own it. Sorry, Nicky."

Hilton said she first became aware of Juicy Couture when friend and publicist Lara Shriftman, who was representing the brand at the time, sent the Hilton sisters a box of outfits.

"I heard a story that [Pamela Skaist-Levy] and Gela [Nash-Taylor] started Juicy couture with $200 and then turned that around into a billion-dollar company, and that is a total girl-boss move," she noted. "Loves it."

"As soon as I put on my first Juicy tracksuit, I was obsessed," she went on. "I said, 'Please send me more. I want the full collection. Every single color.' I just fell in love with the brand, and it basically became my uniform. I have an entire closet that's only Juicy Couture. It's somewhere I go in every single day and just put on my Juice. I was not only wearing them to the airport or to just chill in my house in, I was going out at night in them and I was rocking them with everything. So I think that they loved that I was kind of like the face of the brand."

While Hilton was rocking her Juicy sweats all around town, she got pitched a reality show -- "The Simple Life" -- which she then pitched to longtime friend Nicole Richie. "We've known each other since we were 2 years old," Paris said. "There's nobody who's funnier, has such a personality. I knew that we would make the perfect team."

"They didn't say where we were going, so I didn't even know what to pack. I basically just packed all of my favorite outfits -- included a lot of Juicy, a lot of pink, a lot of heels," she recalled. "Within a month, Nicole and I were on a jet. We landed in this little town called Altus, Arkansas. Both of us had never been anywhere like that. Juicy is something that we wore almost every single day because we are always having to do these jobs, and we didn't wanna just be in like overalls or jeans. We wanted to be comfortable and cute."

Paris had "no idea how huge" the reality show would be, but it changed her life. Gone were the days the socialite could walk out her front door and not be bombarded by paparazzi and reporters.

"I remember after 'The Simple Life' aired, all of the sudden, I started seeing Juicy Couture everywhere. When you looked through any tabloid, everyone was rocking them," Hilton recalled, adding, "It's amazing now to see just so many of these looks that I wore are now on the runway and people are rocking them all the time. It makes me feel proud to have had such an impact in fashion history."

"When people think back on 2000s fashion, the first thing they're gonna think about Juicy Couture," she concluded. "I've never stopped wearing it, and I never will because I'm a Juicy girl for life."