Kim Kardashian reportedly disapproves of half-sister Kylie Jenner's highly publicized relationship with her rumored rapper boyfriend Tyga.

According to Heat, the teen reality star initially began dating the YMCMB emcee for media attention and fame.

"Kylie's worried that she's the least famous in the family, so she started seeing Tyga to get attention, but now she's fallen for him," a source said. "But he won't commit to her at all. He's seeing Kylie, but he's also sometimes seeing his ex -- and there may be other girls, too."

Also, Kardashian is apparently upset that Jenner is currently seeing one of her close friends Blac Chyna's ex-lover.

"At first, she was so angry, she tore into Kylie. Blac Chyna was really upset when they split and to see Kim's little sis hooking up with him? Awful," the source said. "But when Kim say how upset Kylie was, she relented, telling her, 'You're too young to mess with losers like Tyga -- find someone better.'"

Meanwhile, Kardashian is reportedly worried about another half-sister Kendall Jenner having a crush on Chris Brown.

"Kendall is pretty much obsessed with Chris -- she says she's totally 'in love' with him," the source said. "She says she goes weak for him and claims they have this amazing chemistry. She's often sending him pictures and calling at night to 'chat' and to find out where he is. ... Everyone know Chris is bad news and doesn't have a good track record with being loyal. She thinks Kendall would be dating down."

Kim Kardashian's husband Kanye West is also concerned about the model's choice in men.

"Kanye tells her that she needs to make smart decisions, unlike her sisters," the source said. "He points out that Scott [Disick] lives off Kourtney and that Khloé puts men before her career and still ended up with nothing."

However, it seems like Jenner does not care, since she also wants to be even more famous.

"Kendall thinks that if she's a model with a controversial boyfriend, she could be more famous than anyone else in her family," the source said. "Everyone's worried, but it seems she's got her heart set on getting together with Chris."

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