The celebrations never stop!

Kim and Kourtney Kardashian pulled out all the stops to throw their sons Saint and Reign a joint Monster's Inc-themed bash, and it's pretty convenient that their kids are born so close together.

Saint turns 2 on December 5, and Reign turns 3 on December 14. Mason must have wanted his own party, because he shares a birthday with his younger brother, too.

The reality stars set up an ice skating rink and a sledding area with fake snow, and they even had Santa drop by for a visit! Both boys got speciality cakes, with characters James P. “Sulley” Sullivan cake for Reign and a Mike Wazowski cake for Saint.

There will be a lot more parties to plan when Kim, Khloe, and Kylie's babies all arrive around the New Year. What about poor Dream? She never gets the star treatment!

They got the over-the-top genes from momager Kris Jenner!