What makes Kris Jenner tick? Her younger sister, Karen Houghton, is exclusively revealing to In Touch how Kris's twisted childhood made her the woman — and momager — she is today.

“She is a workaholic, a hustler,” Aunt Karen says of her big sister, who wakes up daily at 5 a.m. and heads to her home office to brainstorm new ways to expand the Kardashian empire. “It’s called wanting power, Gucci purses, Bentleys, all the things I don’t care about that she does,” she admits of her materialistic sibling, whose fortune has been estimated at $80 million. But the millionaire and matriarch or the Kardashian franchise did not always have such a luxurious lifestyle.

Kris' early years were not only plagued with money issues, but problems with her father — who reportedly had a drinking problem and died in a car accident when Kris was only 19 years old. She also faced a weight complex when she was younger. “She was kind of chubby when she was little,” says Karen, adding that Kris’ body insecurities eventually led her to get a boob job in her early 30s. "Kris is vain,” says Karen. "The whole world knows it."

Karen feels that her sister works excessively because she is unhappy. “If something is upsetting you, you are either going to hit the bottle, do drugs, go to the gym constantly, or you are going to work,” she tells the mag. “It’s an addiction and it’s because you are unhappy. You do these things because there’s a hole that’s not filled.”

Read the full interview with Karen sharing Kris' childhood secrets — plus learn the identity of Kris' new younger man — in this week's issue of In Touch, on stands now.

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