Kylie Jenner told an LA jury Monday that she and Tyga visited Rob Kardashian to warn him about Blac Chyna and her history of violence and substance use, but that her brother continued his relationship with her anyway.
Jenner testified that Tyga showed her a scar that he said was caused by Chyna slashing him with a knife.
"I was a little concerned based on things I'd heard about Chyna from Tyga," Jenner testified Monday.
Jenner said it was her "duty to express what we knew," but that Rob told her that he would continue the relationship anyway.
Jenner said she didn't remember exactly when the conversation took place, but that she believed Chyna may have already been pregnant with her and Rob Kardashian's daughter, Dream, at the time.
Chyna is suing the Kardashian-Jenners for $100 million, alleging that Kris Jenner rallied daughters Kim Kardashian, Khloe Kardashian, and Kylie Jenner in a smear campaign that cost Chyna tens of millions in future income.
Chyna claims that the four women told defamatory lies to executives from the E! Network that convinced them to cancel her convincing them to cancel her "Keeping Up with the Kardashians" spinoff, "Rob & Chyna" four episodes into shooting the second season.
The Kardashians have denied the allegations in the lawsuit, also filing a countersuit alleging that Chyna attacked Rob during their relationship and said that they were concerned about Rob Kardashian's safety while he dated Chyna, according to the Associated Press.
Chyna arrived in the Kardashian orbit through Tyga, who she dated from 2011 to 2014. They have a son, King Cairo Stevenson.
At the time, Tyga was close friends with Kim Kardashian's ex-husband, Ye, who is formerly known as Kanye West.
Months after Kim Kardashian and Ye's 2014 wedding, Chyna and Tyga split.
Some outlets reported that Tyga and Kylie began dating around that time.
Jenner testified in court that she was never friendly with Chyna, but it wasn't until she heard of a physical altercation between her and her brother that she felt anger towards her.
"I wouldn't really say we had a relationship or friendship," she said.
