The socialite and hotel heiress accepted a proposal from James last weekend. He popped the question while they were enjoying a romantic boat ride on Lake Como in Italy.
According to People, James secretly visited the US before their trip to Italy in order to ask Nicky's parents, Rick and Kathy Hilton, for permission.
Nicky and James are still on holiday in Europe and Nicky, 30, has been keeping fans updated on their travels via Instagram.
So far she hasn't referenced the engagement or given us a glimpse at her (sure to be gorgeous) engagement ring. Come on, Nicky!
Although Nicky is keeping quiet, her older sister Paris shared her excitement at the happy news via Instagram.
"Congratulations @NickyHilton on your engagement! I'm so happy for you! You will be the most beautiful bride! Such a lovely couple! Love you both so much!"
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