Sources told TMZ the 28-year-old reality star has been living at the 27-year-old model's house for the past five days. Kardashian was spotted arriving back at Blac Chyna's gated community in his vehicle Tuesday.
Kardashian and Blac Chyna sparked speculation this week by embracing in a photo the model shared Monday on Instagram. The reality star followed up by posting a close-up shot of Blac Chyna captioned with a key emoji Wednesday.
Kardashian's family is said to be "outraged" by the rumored romance. Blac Chyna was previously engaged to Tyga, who is now dating Kardashian's half-sister Kylie Jenner, and shares 3-year-old son King Cairo Stevenson with the 26-year-old rapper.
"Rob has been lonely for so long, so of course it's great for him to spend time with someone other than his sisters," an insider told People. "Rob has also found an escape from his family nagging him about his health. He has ignored their attempts to contact him."
"Rob likes her and seems to think it's mutual," the source added. "It's just hard to take things seriously since obviously both share a lot of anger toward the [Kardashian-Jenners] ... Rob really seems to get a kick out of all the drama that he is causing."
Insiders told the magazine Kardashian "won't be welcomed back" to sister Khloe Kardashian's home, where he had been staying. The 31-year-old reality star clashed with Blac Chyna's best friend, Amber Rose, after she criticized Kylie Jenner in February.
Kardashian gained 100 pounds in the past three years and has largely retreated from the spotlight. The reality star was diagnosed with diabetes after being rushed to the hospital in December, but is reportedly dedicated to improving his health.