Kylie Jenner and her boyfriend, 'Glitta' rapper Tyga, have been open about their relationship since August when she turned 18. But Jenner is still reportedly worried about Tyga hooking up with his ex-girlfriend, Blac Chyna.

Hollywood Life wrote in an exclusive report that Jenner has even decided to how she would react if Tyga ditched her and got Blac Chyna pregnant.

Jenner is afraid that Blac Chyna could use her child, King Cairo, whom she shares with Tyga, for seducing him. A source told the news site that Jenner is aware that Blac is scandalous and could do anything to ruin Jenner's relationship. The source said that Jenner is very territorial, and marking her spot on Tyga.

In case an affair occurred, Jenner would go ballistic, and might even become violent. An insider told Hollywood Life that if Tyga cheated and slept with Blac, Jenner would completely freak out. The insider said, "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 Jenner will want to kill him".

However, Blac Chyna isn't the only person Jenner needs to worry about. As per the reports, she beefed up her security after an overzealous fan grabbed her hair so hard that it made her head snap back. An insider told Radar Online Tuesday that Jenner is legitimately scared even now. The insider mentioned that she said that her fans will do anything to get to her, and acted as if she is the most famous one in her family.