It's a boy!
In her first post, Pandora, 35, shared a video of herself and Jason setting off confetti cannons with family to reveal the baby's sex.
"💙🎉💗 A little throwback to surprising our parents and brothers with whether this little much-loved baby will be a boy or girl on a small, magical confetti-filled day 😍 #cantwait," the mom-to-be wrote.
Lisa, 61, gleefully celebrated alongside her daughter as blue confetti rained down on the group, who later raised glasses in honor of the exciting news. "It's a boy! I was right!" Lisa sang following the toast.
In a second post, Pandora penned a message to her unborn child alongside an adorable image of the family reacting to the reveal news.
"💙 🎉 you are so loved already little boy, we can't wait to meet you 💙🎉," she wrote. "Also, the shock on my daddy's face is just priceless 😂."
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Lisa shared the same photo on her Instagram page, writing, "A little throwback to Pandy & Jason surprising us with the news that the baby will be a little boy! 💙🎉. Can't wait!!!! #NannyPinky #itsaboy @pandoravt."
Pandora and Jason, who have been together for over 15 years, celebrated their 10th wedding anniversary in August. Pandora debuted her baby bump earlier that month while attending her mother's 5th Annual World Dog Day event in West Hollywood.
"Jason and I are beyond thrilled, and very thankful to be able to start this new adventure," she told E! News at the time. "We are very excited!"
Lisa previously told PEOPLE that she is thrilled to become a grandmother for the first time. "It's very happy news for us after losing my brother, my mother and Giggy in the last three years — it's a blessing," she said.
"I love children, I love being a mother ... it's such welcome news for us," she added.