It seems her new man's family, who was already suspicious of Blac's interest in Rob, now believes he may be using drugs again thanks to the romance.
Insiders tell TMZ a now sober former party buddy of Rob's contacted a member of the Kardashian family about two weeks ago to express concern that Rob had been trying to buy drugs and was back in touch with a substance abusing crew of old friends.
It seems the call came right around the time Khloe tossed Blac and Rob out of her home after discovering them in her kitchen following what looked like a booze-fest.
In 2014, Rob was reportedly smoking copious amounts of pot, using sizzurp and taking a variety of painkillers, all of which seemed to exacerbate the weight and health issues that have since spiralled into a serious diabetic condition.
TMZ's sources also claim Rob's family is concerned he's not taking the insulin or other prescriptions he's been prescribed, which could account for his seeming weight gain.
Blac Chyna was caught with two ecstasy pills in her sunglasses case when she was arrested in Texas on Jan. 29. The day after her release from custody, Rob showed up in his Bentley, which he'd driven to Austin from Los Angeles, to give her a lift home.
While the drama between his family and new flame continues to get messier by the day, Rob's sock company Arthur George appears to be progressing just fine. On Feb. 1, Kris Jenner boasted on social media about the brand's new website in her usual "#proudmama" manner. Never a dull moment.