Corey, 33, who works for Justin Bieber's manager Scooter Braun at SB Projects, was reportedly seen smooching Kris on the cheek as the couple popped champagne and took selfies.
The couple reportedly met in Spain at Givenchy designer Riccardo Tisci's 40th birthday in August. Speculation on their relationship began in late October when they were snapped during what appeared to be a romantic dinner date in Sherman Oaks, Calif., and now the relationship is serious enough that Khloe started inviting Corey to family gatherings.
On Friday, Kris and Corey were joined by Scott Disick, Jonathan Cheban and close friend Malika Haqq, who helped wish Kris a happy birthday with a three-tiered cake and huge blow-up photos of her children.
This special night out came after the Kardashian matriarch spent the day at Disneyland on her actual birthday, Nov. 5, sans Corey. The reality star dressed as Minnie Mouse as she took the theme park by storm.