Kourtney Kardashian is expecting a baby boy [1]! The reality star — who is already mom to Mason, 4, and Penelope, 2 — revealed the exciting news on Kourtney and Khloé Take the Hamptons. "I'm so happy we're having a boy," Kourtney said in Sunday's episode of E!'s hit show. "It's going to be perfect for our family." Her sister Kim Kardashian [2] was on hand for the announcement, capturing video of Mason running to greet their large family with a blue star.

News about Kourtney's third child with longtime partner Scott Disick emerged in June. People confirmed [3] the development, saying Kourtney is due in December. According to the initial reports, the pregnancy was "planned," and Kourtney wants to have "a handful of kids." Kourtney's pregnancy rounds out a busy year for the Kardashian-Jenner crew, during which Kendall and Kylie Jenner came into their own [4], and Kim earned the most "liked" Instagram photo [5] of 2014. Congratulations to the happy family!

Source: Getty/Ethan Miller [6]