Paris Hilton shared a series of throwback photos twinning with her sister Nicky on Monday, Oct. 7, to celebrate her sibling's 41st birthday.

To walk into my party seeing all of my friends, women I admire wearing the collection, looking so beautiful, seeing how everyone styles it so differently, it’s a dream come true.” Nicky and Paris Hilton Keep Fire and Ice Streak Going in Coordinating Holiday Party Dresses and More Looks From the Nicky Hilton for Rebecca Vallance Holiday Collection Party Robert Pattinson,

Nicky Hilton had more than one reason to celebrate on Saturday night. "I can't think of a better birthday," she said of celebrating her 41st at the Bel Air home of her parents, Kathy and Rick Hilton.