Sandberg wore black leather pants, a gray top and a simple black blazer when she stopped by Urth Cafe in West Hollywood. Earlier that day, photos surfaced of the model hugging Disick, 32, outside the Beverly Hills Hotel and they were reportedly seen kissing in the Polo Lounge, the hotel's restaurant.
On Monday, multiple sources told PEOPLE that Kourtney Kardashian's ex is dating the Los Angeles-based model. (Disick's agent did not return requests for comment.)
Disick and Kardashian, 36, ended their nine-year relationship last July after he was spotted getting cozy with another woman during a vacation in Monte Carlo, Monaco.
Disick and Kardashian have three kids together: Mason, 6, Penelope, 3, and Reign, 1.
Earlier this week, the exes were spotted taking their children to a pottery studio and then lunch in Calabasas, California. A real estate source also told PEOPLE that Disick recently purchased a "kid-friendly" $5.96 million home in Hidden Hills, California.
Neither Disick nor Sandberg have confirmed their relationship, but both have been busy posting on social media. On Friday, the model shared a shot of herself cuddling with a small black dog while out in Hollywood and Disick has been busy promoting his upcoming club appearance at 1 OAK in Las Vegas on Friday, Jan. 15.