Justin Timberlake's William Rast Clothing Line

Last, but certainly not least, Ali Wentworth models the "Jerri" skinny jeans, a white silk top decorated with skulls and a blue leather biker jacket.

"You say these jeans are guaranteed to make women's butts look good," Oprah says.

"I stand by that statement," Justin says.

What's the secret? Justin says it's all about the jeans' yoke—the material between the waistband and pockets. "More high-waisted jeans have more distance between the yoke and the waistband," he says.

"You are all up in my yoke," Ali jokes.

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