The tot will turn five on April 12.
Balloon arches were placed throughout the party, which featured life-sized characters, snow cones and Stoney Clover Lane party favors for guests.
The party had a lavish dessert setup that included chocolate dipped pretzels, donuts, cake pops, cupcakes, cookies and more. A cotton candy cart was also on hand for the party.
Additionally, guests got to paint a themed picture, attack a piñata, play tug of war, touch real ocean creatures, and design their own aquarium.
Tristan's attendance at True's party followed Khloe's gushing birthday tribute to him, despite their rocky romantic relationship and his multiple cheating scandals.
Shortly thereafter, a source gave ET an update on Tristan and Khloe's relationship.
"Tristan will always be in Khloe’s life, but she isn't in love with him," the source said of the reality star, who also shares an 8-month-old son with the athlete. "She chooses to be supportive, both publicly and privately, for the sake of their children."
"Khloe has the biggest heart and sometimes that is her downfall," the source added. "She is forgiving, loves with everything she has, and is so loyal, but she is focused on co-parenting and taking care of herself right now."