Rob Kardashian, Courtney Stodden, and More Shocking Celebrity Family Confessions

Rob Kardashian had a crush on his sister, Kim.

When asked about his childhood crushes in an interview, Rob confirmed that he had the hots for Jennifer Lopez and Kim.

Joe Simpson thinks his daughter is sexy.

"Jessica never tries to be sexy. She just is sexy," he said in 2004. "If you put her in a T-shirt or you put her in a bustier, she's sexy in both. She's got double D's! You can't cover those suckers up!"

Shia LaBeouf thinks his mom is sexy.

“Probably the sexiest woman I know is my mother,” he told Playboy. “She’s an ethereal angel. Nobody looks like that woman. If I could meet my mother and marry her, I would. I would be with my mother now, if she weren’t my mother, as sick as that sounds.”

Steven Tyler is attracted to his daughter, Liv.

"How can a father not be attracted to his daughter, especially when she’s a cross between the girl he married and himself?" he said. "Unless he’s an ugly man, a father is always gonna be sexually attracted to his daughter on a certain level.”

Jeremy Irons finds parenting "sexual."

"It is very difficult because children under 16 are immensely attractive," he said in 2005. "Any father will tell you…I remember when my son was 12 and he was like a god. He just went through that sort of golden time for about 18 months. I don't have a daughter but they do the same."

"Parental love is sexual. Children practice on their parents. Girls will flirt outrageously with their fathers because they are practicing. But we should know that that is practice. Boys will flirt outrageously with their mothers in a different way."

He also publicly pondered why "a father could not marry his son" back in 2007.

Donald Trump wants to date his daughter, Ivanka.

"Yeah, she's really something, and what a beauty, that one," he said. "If I weren't happily married and, ya know, her father . . . "

R. Kelly had a crush on his mom.

"I would drink from a cup and turn it around and drink from her lipstick part," he said. "I loved her. I even asked her to marry me one day. I was like nine. She said no."

Angelina Jolie's brother, James Haven, says he's single because of his sister.

"I'm a perfectionist by nature," he said. "Then, because I'm so close to Angie it's like I've already got the perfect woman in my life and it's hard for anyone else to live up to that."

Courtney Stodden has a weird relationship with her dad.

"I accidentally call [my husband] 'dad'—you know, Doug-dad, same thing," she said.

Heidi Klum doesn't mind being naked in front of her parents.

"I think it’s because I grew up in a very easy-going family where my parents were always naked," she said. "My parents are still naked. I mean, it’s not like we’re hippies and we run around naked, but if they happened to be in their room changing or something or someone comes out of the shower, they’re not, like, 'Oh my God. No. Close the door.'"

Jennifer Grant, Cary Grant's daughter, had a crush on her famous dad.

"OK, I had a crush on Dad," she wrote in her memoir. "OK, more than a little crush on Dad."

NEXT: Kim Kardashian, Coco Austin, and More Stars’ Most Shocking Post-Baby Sex Confessions