"Obviously, running around with Mike and Sulley was the highlight of Reign's day," Kourtney Kardashian wrote of her son, who turned 3 on Thursday

By Jen Juneau
December 15, 2017 03:40 PM

Kourtney Kardashian and Kim Kardashian West are giving their subscribers a closer look at their sons’ birthday festivities.

On their respective websites, the sisters each shared new photos from Saint and Reign Aston‘s join bash held earlier this month, featuring a Monsters Inc. theme and winter-wonderland elements like ice skating, sledding on a hill covered in (fake) snow, a visit from Santa and Mrs. Claus and more.

“The kids has such a fun afternoon,” Kim, 37, wrote on her website, noting that the day also included a “fun elf-making craft station” and sharing a variety of adorable photos featuring Saint, who turned 2 on Dec. 5.

“How cute were Saint and Reign’s matching cakes?!” she added of the boys’ coordinating character confections. “Sharing moments like this with cousins [is] the absolute best!”

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Kim Kardashian West and son Saint
| Credit: Courtesy Kim Kardashian West
Kourtney Kardashian and son Reign
| Credit: Courtesy Kourtney Kardashian
North West and Penelope Disick
| Credit: Courtesy Kim Kardashian West
Saint West and Reign Disick’s birthday cakes
| Credit: Courtesy Kim Kardashian West

Two other friendly faces to make an appearance (aside from the boys’ sisters North, 4½, and Penelope Scotland, 5)? Mike Wazowski and James P. “Sulley” Sullivan, the protagonists from Monsters Inc. and its prequel, Monsters University.

“Since the monsters in the movie are blue, purple and green, we used those colors for all the decorations,” Kourtney, 38, wrote of the hybrid-themed event.

She added of her son, who turned 3 on Thursday and sported a Sulley costume of his own for the party, “Obviously, running around with Mike and Sulley was the highlight of Reign’s day, LOL!”

Penelope Disick, North West and Reign Disick with Santa and Mrs. Claus
| Credit: Courtesy Kourtney Kardashian
Saint West and Reign Disick’s joint birthday party
| Credit: Courtesy Kourtney Kardashian

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Kourtney writes that the ice-skating rink was transformed from her basketball court for the party (which she hosted), and that dessert also included s’mores, gingerbread-cookie sandwiches, a cupcake-making station and, for the adults, a coffee station featuring mocha and peppermint lattes.

The mom of three (son Mason Dash also had a birthday on Thursday, celebrating turning 8 at Disneyland and with a balloon Ferarri from aunt Khloé Kardashian) went all out for the day, making sure to have a plethora of not only sweets but a large lunch buffet and lots of photo ops.

“We had Santa and Mrs. Claus come and take photos with the kids — so we set up a few photo zones for families to pose together,” Kourtney explained. “I also put outdoor rugs and oversized pillows on the lawn in a few different places, so kids could hang out in the shade.”