Celebrity Parents KarJenners Celebrate Mason's Birthday with Fortnite Party — and Reign Helps Blow Out the Candles Just one day after Mason officially turned 9, the entire KarJenner clan got together to throw a massive bash in his honor By Maria Pasquini Maria Pasquini Associate Editor, Human Interest - PEOPLE People Editorial Guidelines Published on December 16, 2018 11:22 AM Share Tweet Pin Email Birthday royale! Just one day after Mason Disick officially turned 9, the entire Kardashian clan got together to throw a massive bash in honor of Kourtney Kardashian and Scott Disick’s eldest child. This year’s theme paid honor to the popular video game Fortnite, and the party featured giant video screens where partygoers could try their hand at being the last one standing, as well as a light-up dance floor, custom apparel, and a giant sign spelling out Mason’s name. Khloe Kardashian/Instagram When it came time for the birthday boy to blow out the candles on his special cake — which had nods to the game — Kourtney lifted up Mason’s younger brother Reign, who was also born on Dec. 14, to help blow out the candles. Want all the latest pregnancy and birth announcements, plus celebrity mom blogs? Click here to get those and more in the PEOPLE Parents newsletter. Kendall Jenner/Instagram Kourtney Kardashian/Instagram Kris Jenner, Kim Kardashian and Scott Disick Wish His Sons Reign and Mason a Happy Birthday The party was also attended by KarJenner siblings Kim Kardashian West, Khloé Kardashian — who brought along her daughter True — Kendall Jenner and Kylie Jenner, as well as the family matriarch Kris Jenner. The Good American co-designer, 34, shared several posts on her Instagram Story as she walked around the party cradling her daughter in her arms, and in one sweet video, Kylie leaned in to give baby True a kiss on the forehead. Kourtney’s on-again, off-again fling Luka Sabbat, who recently turned 21, was also present, and appeared in one of the videos the mother of three, 39, shared on social media. In the clip, the model — who has long been a friend of the family — was seen taking some swings at a piñata. Khloé Kardashian and daughter True. Khloe Kardashian/Instagram Luka Sabbat. Although the night was a family affair, Mason’s father Scott was not present, as he was traveling abroad with girlfriend Sofia Richie. On Saturday, the couple both posted photos of themselves posing in the Saudi Arabian desert. Saint and Reign Celebrate December Birthdays with Tarzan-Themed Bash & Custom ‘Merch Shirts’ A source tells PEOPLE that although Saturday seemed to be all about Mason, Kim, Kourtney and Kris took the kids to Disneyland on Friday in order to celebrate both Mason and Reign’s birthdays. “They all had fun at Disneyland,” the insider shares. “They went on their favorite rides and the kids were so excited. Despite the Kanye and Drake drama, Kim seemed fine. You could tell she just wanted the kids to have the best day.” Although the famous family has yet to share many photos from the fun night out, Kourtney did post one picture of Cinderella’s castle at night on her Instagram story. Kourtney Kardashian/Instagram Reign previously celebrated his fourth birthday earlier in December with a joint Tarzan-themed bash with Kim’s son Saint. RELATED VIDEO: Sofia Richie ‘Knows’ Kourtney Kardashian Isn’t Her ‘Biggest Fan’ and Tries to ‘Deal’: Source In honor of both of her birthday boys, Kourtney shared a sweet tribute to her sons describing them as “the two coolest boys in the world.” “I woke up yesterday with my heart so happy that God blessed me with the two coolest boys in the world. Such a bond. Happy Birthday Mason and Reign!” she wrote, alongside shots of the pair soaking up the sun together. Disick also shared a sweet tribute of his own. “Happy birthday my loves! ❤️” wrote the father of three on Friday, alongside a snapshot of his sons from the back on board a speedboat, which depicted Reign whispering something in Mason’s ear.