"She can't write or sing or dance, so she does harmful things in order to validate herself in the media," Kim's ex-husband, Damon Thomas tells In Touch exclusively. "That's a fame-whore to me. It's just not cool at all."

Kim Kardashian wants the world to think that she's the perfect, supportive sister who would do anything for her family. But in an exclusive interview with In Touch, Kim's ex-husband says that behind closed doors, Kim has a very different -- and troubling -- set of priorities. "Kim is obsessed with fame," Kim's ex, music producer Damon Thomas, reveals, adding that even when he was in love with her, Kim struck him as the type of person who would step on anyone in order to get where she wanted -- including her sisters, Khloé and Kourtney. "She's jealous and competitive with her sisters," he shares. Desperate to be famous, Damon says, Kim doesn't seem to care whom she hurts -- whether it's friends, lovers or even her own family. "She can't write or sing or dance, so she does harmful things in order to validate herself in the media," he says. "That's a fame-whore to me. It's just not cool at all." And while a rep for the Kardashian sisters says they're "best friends and very supportive of one another," Damon disagrees. "Jealousy is a big thing" with Kim, he says, revealing that when he knew her, Kim would "do whatever it takes" in order to get ahead.

If Kim's sisters feel wronged by her, Damon says, they aren't the only ones. In fact, he believes Kim was behind the recent release of court papers, filed during their 2003 divorce, in which she claimed he beat her -- a claim he emphatically denies. "It's just absolutely not true," he says, adding that Kim never filed for a restraining order or a protective order throughout their marriage, and simply accused him of abuse in order to get "a lot of money" out of him. Damon says, he was the one who filed for divorce first. And he did it because Kim was cheating on him with "multiple guys." Kim has denied this claim. Still, Kim managed to lure Damon back into the relationship for a brief time, during which, he says, she convinced him to finance extravagant shopping sprees and extensive plastic surgery -- including a boob job and liposuction. "She wanted to have that lifestyle," he explains. "She wanted to be what she ultimately became." And Damon was willing to finance it -- until he saw her on the cover of a magazine on a date with Jennifer Lopez's ex, Cris Judd. "I saw my wife with another man, wearing the clothes that we had just bought after her lipo," he says. "It was not something as a husband you ever wanted to see."

For the full exclusive interview with Damon, pick up this week's In Touch, on newsstands Friday.