Shortly after, Kylie Jenner took to her Instagram story to share a few photos from the engagement dinner -- including one tightly cropped screenshot showcasing the new ring.
"This oval diamond is spectacular at around eight to 10 carats on a thin pave diamond band, most likely set in platinum, as it will hold the diamonds more securely," Jenny Luker, President, PGI USA Jewelry Inc., told ET of the ring. "Also, since platinum lasts for generations, this ring will likely become an heirloom that Kourtney could pass along to her children. I would estimate this ring costs north of $500,000."
"Kourtney and Travis are over the moon. Getting engaged was always their natural next step and they are so thrilled," the source said. "The proposal was gorgeous and romantic, and everything Kourtney wanted."
"Their families are beyond happy and excited for them too. Their kids are very much looking forward to being an official big happy family," the source added. "Kourtney and Travis really feel like they've found their perfect partner and match. They can't wait for this next step in their journey as a couple and to spend the rest of their lives together."
Kourtney, 42, and Travis, 45, have been longtime friends and neighbors, and started dating in January. The two quickly got serious, taking family trips with their respective kids. Kourtney shares three children -- 11-year-old Mason, 8-year-old Penelope and 6-year-old Reign -- with her ex, Scott Disick. Meanwhile, Travis is dad to two children with his ex-wife, Shanna Moakler -- 17-year-old Landon and 15-year-old Alabama.