Khloé Kardashian and Tristan Thompson 'Had Very Little Interaction' at True's Birthday: Source

"Khloé seemed a bit nervous about having him there, but there was never a question if he would be invited," a source tells PEOPLE

Khloé Kardashian wanted Tristan Thompson to be at their daughter’s first birthday party last weekend, but that doesn’t mean the exes spent much time together there.

“Tristan attended the birthday party with some friends,” a source tells PEOPLE. “Khloé seemed a bit nervous about having him there, but there was never a question if he would be invited.”

The source explains that despite their differences, the Keeping Up with the Kardashians star, 34, doesn’t want to get in the way of the basketball player’s relationship with True.

“It’s super important to Khloé that True spends as much time with Tristan as possible. Khloé wants True to have a great relationship with Tristan,” the source adds.

True’s party marked the first time her parents have been seen together since his cheating scandal involving family friend Jordyn Woods.

Khloé Kardashian and daughter True. Richyoungin / Instagram

Although Kardashian may have been nervous about inviting her ex to attend Sunday’s celebration — especially given her family’s anger over the betrayal — the lavish bash was a success.

“Everything went smoothly,” the source says, adding that “Khloé had asked her family to behave and leave Tristan alone.”

While Thompson, 28, made a brief appearance on Kardashian’s Instagram Story as the pair took some photos with the birthday girl, the source said that was pretty much the extent of their contact with each other.

“Khloé and Tristan posed for some pictures together with True, but otherwise had very little interaction,” the source says. “Khloé let Tristan spend some alone time with True.”

True Thompson and Khloé Kardashian. Khloe Kardashian / Instagram

In a super sweet video posted on his own Instagram account, the NBA player held his baby girl in his arms, telling her she deserves “all the jewels.”

“❤️❤️my princess❤️❤️ I love you soo much,” he captioned the clip.

In true Kardashian form, the reality star went all out for her daughter’s big day — even getting matching mommy-daughter designer dresses for the occasion.

The outdoor celebration was filled with butterfly decorations, cotton-candy vendors, a dreamy dessert table, toddler-friendly play equipment and “unicorns” with colorful horns and pink manes that younger guests could ride around the event.

“Khloé was very excited how the party turned out,” the source says. “It was all over the top and insane of course. But It was very important to Khloé to have this party. True is her life and she just wanted the most special day with her girl.”

Tristan Thompson/Instagram

The party was attended by Kylie Jenner, Kim Kardashian West, Kourtney Kardashian and Khadijah Haqq. (Khloé’s sister Kendall Jenner was spotted at the Coachella Music and Arts Festival in Indio, California.)

True’s older cousins Stormi, 14 months, Chicago, 15 months, and North, 5½, were also there.

Khloe Kardashian / Instagram

Khloé Kardashian’s Instagram Story. Khloe Kardashian / Instagram

Khloé recently told PEOPLE she’s in disbelief that her baby is about to hit the one-year mark.

“It’s so corny but you don’t realize how fast time goes by until you see a child growing in front of you,” she said. “It’s scary and sad because it goes so fast. Can we slow down time?”

But the reality star has never been happier than she is with her daughter: “I am so utterly obsessed with her. This first year has been amazing. And I really feel like I was meant to do this.”