“Keeping Up With the Kardashians” star Kylie Jenner and her boyfriend, “Glitta” rapper Tyga, have been public about their relationship since she turned 18 in August, but she’s still reportedly worried about him hooking up with his ex-girlfriend, Blac Chyna. Jenner even knows how she would react if Tyga cheated on her and got Blac Chyna pregnant, Hollywood Life wrote in an exclusive report Tuesday.

Jenner is afraid that Blac Chyna might use her child, King Cairo, whom she shares with Tyga, to seduce him. “[Jenner] knows Blac’s scandalous and would do anything to ruin [Jenner's] relationship,” a source told the news site. “Kylie’s very territorial and she’s marking her spot on Tyga!”

If an affair occurred, Jenner would go ballistic. She might even become violent. “If Tyga cheats and sleeps with Blac, Kylie would completely freak out," an insider told Hollywood Life. “But that will pale in comparison if he ends up knocking Blac up! If for some reason Tyga does something that incredibly dumb, he better go into the witness protection agency because Kylie will want to kill him.”

But Blac Chyna isn’t the only person Jenner has to worry about. She reportedly beefed up her security after an overzealous fan grabbed her hair so hard it made her head snap back.  “Kylie is still legitimately scared. She says that her fans will do anything to get to her,” an insider told Radar Online Tuesday. “She is acting like she thinks that she is the most famous one in her family.”

Jenner hasn’t addressed the security problem or Blac Chyna rumors in public. But one hot topic she did talk about was plastic surgery. She wrote a post on her app called “My Feelings On Plastic Surgery: The Whole Truth.” She said she has never had plastic surgery, only lip fillers, but her motto is “never say never” when it comes to cosmetic enhancement.

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