Khloe, along with sister Kourtney and mom Kris, were spotted arriving at Tristan's Los Angeles home on Saturday. On her Instagram Story, the reality star shared several pics of balloons and red, white and blue decorations, but nothing more from the festivities.
The source adds that the same is true of Kylie Jenner and Kourtney Kardashian with regard to their exes -- Travis Scott and Scott Disick, respectively. Scott was spotted spending time with his recent ex, Sofia Richie, over the Fourth of July weekend.
"They’re all family," the source said. "Everyone gets along and everyone has the kids’ best interests in mind."
Another source told ET that Khloe "is being cautious" with Tristan.
"At the end of the day Khloe wants her daughter, True, to have both her parents around as much as possible, and if they can make it work, she wants to try," the source added. "Khloe has gone through a lot and has reiterated that to Tristan, who insists he has changed.”
A separate source previously told ET that the couple were isolating together amid coronavirus shutdowns and were enjoying their time with True, noting, "This alone time has really allowed them to reconnect without outside influences."
Rumors of a rekindled relationship have been swirling following Khloe's 36th birthday bash, where Tristan was in attendance with her family and friends. The NBA star also penned a sweet birthday message for Khloe on Instagram, and shared it with a photo of him and Khloe playing with their little girl.
"I’m wise enough now to know, you came into my life to show me just what it means to be an incredible person. I appreciate how I am able to learn from and grow because of you," he wrote. "I thank God for the beautiful and loving woman you are to everyone, especially our daughter True. You deserve the world Koko! True and I love you mama. Happy Birthday @khloekardashian."
Khloe and Tristan split in February 2019, following his cheating scandal with Jordyn Woods, but have since built a positive co-parenting relationship for True. In addition to quarantining together, the pair was spotted hanging out at a friend's party last month.
Check out the video below for more on their relationship.