Brewer was a 23-year-old model when she met Trump in Miami in 1990. She was invited to his home and they immediately hit it off.
"It was a spark from the beginning," she said. "He was a gentleman. He was funny!"
In public, he had "that air about him," she said, but in private, he was a different person. "More gentle," she said.
The first time it struck her that she was dating a famous billionaire was when they attended a Christmas party together and paparazzi followed them. Trump's bodyguard warned Brewer to call her mother to tell her about the relationship before she read about it in the newspapers.
What Trump did next was the "sweetest thing he ever did," Brewer recalled.
"Donald called my mother," she said. "He said, 'You have a beautiful daughter.' ... It made me laugh."
But their relationship was short-lived. Their jobs took them in different directions and they ultimately went their separate ways, she said.
"He was on one coast, I was on the other," she explained. "He had so much important business to take care of."
But while she missed out on potentially becoming first lady, Brewer, who has a daughter, has no regrets.
"I love where my life took me," she said.
For more of INSIDE EDITION's exclusive interview with Brewer and to find out how she reacted when Trump announced he'd be running for president, tune in on Friday.
See photos of Melania Trump through the years:
Melania Trump through the years
Trump's ex-girlfriend reveals the sweetest thing he ever did for her
Melania Knauss and Donald Trump sit ringside for the Lennox Lewis-Michael Grant WBC/IBF Heavyweight Championship fight Saturday, April 29, 2000, at New York's Madison Square Garden. (AP Photo/Mark Lennihan)
New York mayoral hopeful Michael Bloomberg, real estate developer Donald Trump, and model Melania Knauss chat together at the Bloomberg pre-dinner party for the White House Correspondent's DInner at the Washington Hilton, Saturday April 28, 2001 in Washington. (AP Photo/ Bloomberg, John Harrington)
Donald Trump, left, watches a match between Roger Federer, of Switzerland, and Robby Ginepri, of the USA, with model Melania Knauss at the US Open tennis tournament in New York, Thursday, Aug. 30, 2001. (AP Photo/Richard Drew)
Melania Knauss, left, and Donald Trump arrive at the opening night party for Britney Spears' restaurant Nyla, at the Dylan Hotel in New York, Thursday, June 27, 2002. (AP Photo/John-Marshall Mantel)
**FILE**Donald Trump and Melania Knauss pose as they arrive for a charity event on board the Queen Mary 2 on April 24, 2004 in New York. The couple weds Saturday evening, Jan. 22, 2005, in Palm Beach, Fla. (AP Photo/Stuart Ramson)
Melania Trump poses for pictures as she arrives at the Costume Institute Gala held at the Metropolitan Museum of Art in New York, Monday , May 2, 2005. (AP Photo/Stuart Ramson)
Photo by: Mitch Gerber/starmaxinc.com
ALL RIGHTS RESERVED
Telephone/Fax: (212) 995-1196
Donald Trump and Melania Knauss at the premiere of "War of the Worlds".
(NYC) (Star Max via AP Images)
Donald Trump and his wife Melania Knauss wait for the start of the showing of the Oscar de la Renta spring 2006 collection, Monday, Sept. 12, 2005, during Fashion Week in New York. (AP Photo/Diane Bondareff)
Donald Trump with his wife Melania arrive at The Jazz at Lincoln Center for a gala event celebrating Qatar Airways' inaugural flights to New York, Thursday, June 28, 2007, in New York. (AP Photo/ Louis Lanzano)
Melania Trump attend a screening of "The Duchess" hosted by The Cinema Society, Chanel and Vogue in New York on Wednesday, Sept. 10, 2008. (AP Photo/Peter Kramer)
Melania Trump attends The Museum of Modern Art Film Benefit honoring Baz Luhrmann on Monday, Nov. 10, 2008 in New York. (AP Photo/Evan Agostini)
Melania Trump arrives before the 83rd Academy Awards on Sunday, Feb. 27, 2011, in the Hollywood section of Los Angeles. (AP Photo/Matt Sayles)
Melania Trump attends the 'Dressed To Kilt' fashion show to benefit the Friends of Scotland Organization at the Hammerstein Ballroom on Tuesday, April 5, 2011 in New York. (AP Photo/Evan Agostini)
Donald Trump and Melania Trump attend the premiere of "Tower Heist" on Monday, Oct. 24, 2011, in New York. (AP Photo/Peter Kramer)
Melania Trump arrives at the Metropolitan Museum of Art Costume Institute gala benefit, celebrating Elsa Schiaparelli and Miuccia Prada, Monday, May 7, 2012 in New York. (AP Photo/Charles Sykes)
"Celebrity Apprentice" host Donald Trump and his wife Melania Trump arrive for the NBC network upfront presentation at Radio City Music Hall, Monday, May 14, 2012 in New York. (AP Photo/Evan Agostini)
Melania Trump pose for photos at a news conference, in New York, Thursday, May 1, 2014. (AP Photo/Richard Drew)
LAS VEGAS, NV - December 15, 2015: Donald Trump and Melania Trump pictured in the Spin Room at the CNN GOP Debate at The Venetain Resort in Las vegas, NV on December 15, 2015. Credit: Erik Kabik Photography/ MediaPunch/IPX
Republican presidential candidate Donald Trump leaves the stage with his wife Melania Trump and his daughter, Ivanka Trump. left, after the first Republican presidential debate at the Quicken Loans Arena Thursday, Aug. 6, 2015, in Cleveland. (AP Photo/Andrew Harnik)
Donald Trump is joined by his wife Melania in the spin room following the CNN Republican presidential debate at the Venetian Hotel & Casino on Tuesday, Dec. 15, 2015, in Las Vegas. (AP Photo/Mark J. Terrill)