Multiple sources tell ET that the reality star and professional basketball player recently decided to go their separate ways. They share one child together, 3-year-old daughter True.
"Khloe and Tristan broke up recently. Tristan was at a birthday party in Bel Air on Friday night and was acting very single throughout the evening," the source says. "The Kardashians were invited to the party but did not attend. Tristan and Khloe will continue to co-parent True together in a healthy, loving way."
According to a second source, Khloe and Tristan "ended their relationship a few weeks ago."
"Khloe gave Tristan several chances and after new allegations decided it was time to break things off," the source says. "The two are on good terms and at the end of the day, Khloe just wants True to have a good relationship with her father."
"I knew, OK, my daughter is gonna want to see her birth video one day, I would hope," she recalled. "I wanted to think about True in that moment and say, 'This is not about me. We're gonna handle this on our own, later. This should not ever affect my child.' And I wanted to have these memories to have these moments for her."
Khloe told Andy that she initially took Tristan back the first time because she was "overwhelmed" by all the media attention and pressure after welcoming her first child. When rumors started swirling that Tristan cheated again, however -- this time with Kylie's then-BFF, Jordyn Woods -- it was a longer road to reconciliation. She revealed they only recently rekindled their romance after co-parenting together throughout the COVID-19 pandemic.
According to Khloe, she and Tristan weren't together when they filmed the 20th and final season of KUWTK. "And then, I don't know, we just really, really became genuine great friends with one another," she explained. "It just was this natural progression. I'm not saying that's what I would encourage other people to do, it's just what naturally happened with him and I."
When Andy bluntly asked Khloe if she trusts Tristan now, she responded, "I mean, I definitely trust him as a friend and all those things."
"What I need to find out, everything comes my way," she added. "I just need to trust and focus on today and go day by day. I can't worry too much about everything else."
News of their most recent breakup comes amid reports that Khloe threatened to take legal action against a woman who is claiming that Tristan fathered a child with her. Khloe is reportedly suing the woman, Kimberly Alexander, for defamation, claiming that she fabricated direct messages to make it look like she and the reality star had a conversation over Instagram.
Khloe's attorney, Lynda B. Goldman of Lavely & Singer Professional Corporation, claimed in court documents obtained by ET that "a DNA test from one of the nation's top labs confirmed that Mr. Thompson is not the father of [Kimberly's] child."
Additionally, Instagram model Sydney Chase claimed during an April interview that she hooked up with Tristan back in the fall. Tristan has vehemently denied her claims.
News of Khloe and Tristan's split also comes ahead of her upcoming 37th birthday on June 27. In honor of her special day last year, Tristan gushed over his "beautiful and loving" girlfriend and the lessons she's taught him over the years.
"I'm wise enough now to know, you came into my life to show me just what it means to be an incredible person," the NBA star wrote at the time. "I appreciate how I am able to learn from and grow because of you. I thank God for the beautiful and loving woman you are to everyone, especially our daughter True."
"You deserve the world Koko!" he added. "True and I love you mama. Happy Birthday @khloekardashian ❤️"
It appears Khloe's last Instagram photo featuring Tristan -- a birthday post for her brother, Rob Kardashian -- was shared on June 8. Prior to that, she hadn't posted any pics with Tristan to her feed since March 13, which marked his 30th birthday.
"The ones that are meant to be are the ones who go through everything that is designed to tear them apart and they come out even stronger than they were before," she wrote. "Thank you for showing me everything you said you would. For the father you are, for the best friend I have in you. I'm thankful that I can do absolutely nothing with you and it feels like everything."
"I hope you know today and every day how loved you are by me and so many," she added. "Happy birthday TT! Welcome to 30! I can't wait for all of the memories. This is when life just starts getting good!"
The two eventually reignited their romance. Since then, Khloe has been open about her and Tristan's relationship ups and downs during the past few seasons of Keeping Up With the Kardashians. In recent episodes from the final season, Khloe got candid about everything from potentially moving to Boston (where Tristan plays for the Celtics) to saying "I do" for a second time (she was previously married to Lamar Odom) and having more kids with Tristan in the future.
"I hope I have a sibling for True, but also I don't feel incomplete if I don't," Khloe said, when asked by sister Kim Kardashian West where she sees herself in 15-20 years. "I think I want to be married again. I think. But I also don't think I need to be married again in order to feel like this is our union."