Tristan Thompson/Instagram Khloe Kardashian and Tristan Thompson with True
"Tristan is back in L.A. to celebrate Father's Day with Khloé and True. He spent a lot of time away from L.A. during the [basketball] season," the source explained, adding that "Khloé is happy to have him back."
"She and Tristan are good. They are planning some summer vacations together," the source continues. "They also still talk about giving True a sibling."
On Sunday, the proud dad shared a post on Instagram of himself posing beside his son Prince Thompson, 4½ - whom he shares with ex Jordan Craig - as well as a shot of himself smiling beside his daughter with Kardashian, 36.
"In the past few months, Tristan has really shown Khloé that he has changed," a source previously told PEOPLE. "He is an amazing dad and partner."
Earlier this year, Kardashian shared a loving message on social media in honor of the athlete's 30th birthday. At the time, the mother of one called Thompson her "best friend" and praised his relationship with their daughter.
"The ones that are meant to be are the ones who go through everything that is designed to tear them apart and they came out even stronger than they were before," she wrote alongside several images of the family of three spending time together. "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," Kardashian continued. "I hope you know today and everyday how loved you are by me and so many."