The parents to son Mason, 4, and daughter Penelope, 2, publicized their happy news in the latest episode of Kourtney and Khloe Take the Hamptons.
In an installment called "Kaptain Kourtney and Skipper Scott," the longtime pair are shown telling their family and explaining how they broke the news of their new addition's gender to their two older children.
"We're having a boy," Disick, 31, said, looking intimidated by the prospect. Asked by Kourtney's sister Khloe Kardashian if his reaction meant he wasn't excited, the reality star said, "No, I'm fine now! I'm excited!"
Kourtney, 35, added that little Mason was involved in the reveal. "Mason ran in here with the blue stick," she told Khloe. "There was a red star or a blue star."
Mason could share a birthday with his little brother, as Kourtney is expected to give birth in the coming weeks and Mason's fifth birthday is on Dec. 14.
"I am so happy that we're having a boy," the expectant mother continued in the episode. "It's going to be perfect for our family."