Paris Hilton Celebrates Boyfriend Stavros Niarchos' 21st Birthday Party at Light Nightclub at The Bellagio Hotel and Casino Resort [Getty Images]

(EXCLUSIVE, Premium Rates Apply) Paris Hilton and Stavros Niarchos - Exclusive Coverage (Photo by Denise Truscello/WireImage) — see more

(EXCLUSIVE, Premium Rates Apply) Paris Hilton and Stavros Niarchos - Exclusive Coverage (Photo by Denise Truscello/WireImage)

WireImage Denise Truscello