After baring it all
magazine, Kourtney Kardashian finally caved and revealed the sex of her third child on Sunday's Kourtney & Khloe Take the Hamptons.
And it looks like Penelope and Mason will be welcoming a baby brother!
On the show, Kim Kardashian shares a video of the moment Kourtney finds out she's having a boy -- due later this month -- and vieres hear the excited screams that come from the mom-to-be.
Per usual, Mason steals the episode, saying, "I wanted a girl." Aunt Khloe Kardashian assures him that a little brother is better as he can "boss him around."
Mason's mom, however, is ecstatic about the sex. "I am so happy we're having a boy," Kourtney says. "It's going to be perfect for our family."
What do you think Kourtney should name her baby boy? Leave some suggestions in the comments and tweet #ETnow.
There might be another pregnant Kardashian sister coming soon
. Kim recently revealed to ET that she and Kanye West are trying for baby No. 2! "You know I kind of wish I was pregnant at the same time Kourtney is," she said back in August. "She's like more than half way in, so you know, we're trying."