We're told it all went down last week, when Khloe returned home early from a trip promoting her new show. She walked into the kitchen and found Rob and Chyna standing there. There were liquor bottles and trash strewn about, and it appeared the 2 had been there for days.
Our sources say Khloe became enraged and asked Chyna, "What the f*** are you doing in my house?" The 2 bolted into Rob's wing and locked the door ... Khloe followed suit and told them both to "get the hell out." Khloe made it clear to Rob, he was no longer welcome in her home.
We're told Khloe's view was that she was exercising tough love on Rob, because she felt he was falling off the wagon and Chyna was preying on him.
Our sources say Rob's family was especially indignant when she learned Rob had purchased some expensive items for Chyna, and he doesn't have a lot of money to burn.
And we're told, there's a reason there's bad blood between Chyna and the Kardashian women. We're told when Tyga first hooked up with Kylie, Chyna followed Kylie around and harassed her. The sources say she also sent her threatening messages.