NICKY HILTON says that she and sister PARIS HILTON enjoy an ongoing inside joke about Nicky's home design ideas -- and her older sibling's penchant for stealing them.

"I told her she isn't allowed to come over if she copies me," says Nicky in the new issue of InStyle, on newsstands Friday. In the mag, Nicky shows off her sweet L.A. crib!

A 5,000-square-foot, four-bedroom and five-bath 1950s ranch home located just above Hollywood's Sunset Strip, Nicky is proud that her first home's décor reflects her taste and maturity.

"I don't want my house to look like a page you see in a catalogue," says the budding fashion designer, who has surrounded herself with an elegant French Regency style, punctuated with some modern touches.

"I like drama -- when it comes to design," she says, adding that her house "is a rebellion" against the very fancy and pink hotels she grew up living in as the great-granddaughter of CONRAD HILTON, who started the Hilton Hotel chain in 1946.

"Growing up in hotels, I was definitely spoiled," says Nicky. "I miss having fresh sheets and room service every day. Still, it's nicer to have my own house."

Check out more with Nicky at InStyle.com/click2play, featuring new, exclusive videos of celebrity interviews, behind-the-scenes tours and fashion, and beauty scoops straight from the pages of InStyle.