Kimberly Guilfoyle and Donald Trump Jr.'s Relationship Timeline: Everything to Know About Their Romance as Split Rumors Swirl

Kimberly Guilfoyle and Donald Trump Jr. had known each other for decades before they started dating. They were pictured at several events in the late 2000s, along with his then-wife, Vanessa Trump.

In March 2018, Don Jr. and Vanessa released a statement confirming their split after 12 years of marriage.

"We will always have tremendous respect for each other and our families," they said in a statement. "We have five beautiful children together and they remain our top priority. We ask for your privacy during this time."

Don Jr. later moved on with Kimberly, with Page Six reporting the two were "having a great time" together. They were spotted attending a party for Donald Trump's ambassador for Germany, Richard Grenell, before they had dinner in New York City.

Months after the dating rumors began, Don Jr. debuted their relationship on Instagram, sharing their photo with the band Poison.

According to reports, Don Jr. popped the question to Kimberly on New Year's Eve 2020 but decided to keep the news under wraps.

"They've been together for almost four years now and have been friends for 15 years," a source told Daily Mail, adding, "They've kept it private for the past year as they settled into life in Florida after moving from New York. Both are focused on their children — they have six between them — and their work."

The former Fox News host celebrated Don Jr.'s special day with a heartfelt Instagram post in which she was seen wearing a diamond ring on her left ring finger.

"Tonight was extra special celebrating @donaldjtrumpjr's birthday," she wrote. "Don, you are strong, smart, courageous, funny and the love of my life. I can't wait to spend the rest of our lives together. Love you."

Neither Don Jr. nor Kimberly had confirmed the engagement buzz at the time.

After weeks of speculation, Kimberly formalized their relationship status in a Valentine's Day Instagram post.

"Falling in love with my fiancé more and more every day," she captioned the update. "@donaldjtrumpjr, you're my best friend, my support system and my forever guy. Happy Valentine's Day, I love you and can't wait for the adventures that lie ahead."

To celebrate their anniversary, Don Jr. took to Instagram and shared their sweet photos together.

"Thanks for always being there no matter what the haters are throwing our way," he wrote in the post. "I love you."

The Daily Mail released a report in September, saying the President-elect's son was spotted canoodling with socialite Bettina Anderson during a brunch in August despite his engagement to Kimberly.

"She seemed totally smitten with Don – and he with her," a source said. "They looked totally relaxed, she wearing a white shirt tied off to show her midriff and wide leg pants, he in shorts and a T-shirt."

An insider also noted the two appeared to be on a date at the time, explaining, "They weren't exactly making out, but the kisses were romantic, and you could tell they were intimate with each other."

Don Jr. and Bettina made headlines again after photos published by a news outlet showed the pair holding hands during a date.

According to the report, they stayed at Buccan in Palm Beach, Fla., for two hours to celebrate her birthday. They were also pictured going to a bakery days before the night out.

Sources told that Don Jr. and Kimberly parted ways amid the cheating scandal.

"Don and Kimberly haven't been getting along over the past year," one insider said. "They get argumentative at Mar-a-Lago in front of people. Nothing crazy, but you know when a couple is fighting. They bicker in public."

Other sources claimed they'd split, while some said the relationship already became "rocky."

Don Jr. later addressed the rumors, stating, “Kimberly and I will never stop caring for each other and will always keep a special bond."

“I could not be more proud of her and the important role she’ll continue to play in my father‘s administration,” he added of Kimberly, 55, who was recently appointed to be ambassador of Greece by Donald, 78. "Anyone taking baseless and petty fake news cheap shots at her in the tabloids are just embarrassing themselves."