The Blink-182 drummer gave a drumroll before confetti shot in the air.
In a very appropriate gender reveal moment, Kourtney sat on the Blink-182 drummer's lap as he gave a drumroll before slamming the cymbals as blue confetti rained down on them and a mass of blue streamers filled the air.
The happy couple, who were both dressed in white, celebrated with a kiss, giving each other a sweet hug as their friends and family cheered.
Kourtney publicly announced that she was pregnant last week in the audience at a Blink-182 show. The 44-year-old reality star jumped up and down holding a sign that read, "Travis I'm Pregnant," a callback to a moment from the band's "All the Small Things" music video.
Both Kourtney and Travis have children from previous relationships. Kourt shares three children -- 13-year-old Mason, 10-year-old Penelope and 8-year-old Reign -- with her ex, Scott Disick. Meanwhile, Travis has two kids with his ex-wife, Shanna Moakler -- 19-year-old Landon and 17-year-old Alabama. He also cares for Moakler's daughter, Ariana De La Hoya, from her past relationship with Oscar De La Hoya.
Following the baby news, a source told ET that Kourtney and Travis are on "cloud nine."
"Kourtney and Travis are on cloud nine. This pregnancy is beyond Kourtney's wildest dreams. Kourtney and Travis feel like this is one of the most magical things to happen to them and a complete miracle," the source shared. "They are so thrilled and can't wait to experience this pregnancy together, bring a baby into the world as a unit, and expand and grow their families."
As for how reality TV star's ex, Scott, is feeling about the baby news, a source told ET that "Scott is being as supportive as possible."
Travis' ex-wife, Shanna, told ET, "I'm very excited for them. Hope they have a great experience bringing in a new life to the world."
The couple has been trying to get pregnant for years, trying out IVF and other fertility treatments. In the season 3 premiere of The Kardashians, Kourtney shared that they were done trying IVF and were hoping to get pregnant naturally.