And we're SO pleased Paris has been sharing photos with us of the celebrations!
The sisters are currently in Miami, Florida, marking Nicky's last days as a single lady before she marries fiancé James Rothschild.
And naturally the girls and their friends look oh-so-glam... We really wish we'd been invited it looks so much fun!
Our favourite Paris outfit has to be the bright pink lace number she wore to Nicky's official 'Ultimate Bachelorette Party' at Wall at W Hotel on Saturday night (6 June).
True to form, the blonde heiress pimped up her outfit with cute kitten ears!
Paris tweeted: "Round 2! #BridesMaids ready to #Killit at @WallMiamitonight! #NickysBachelorette #MrsRothschild."
The girls had spent the day partying on a boat in the Miami sunshine.
Paris also tweeted: "So happy to be celebrating my sister @NickyHilton's bachelorette party with my beautiful family this weekend! #Blessed #BridesMaids #MrsRothschild."
Nicky got engaged to her banking heir boyfriend James in August.
The socialite and hotel heiress accepted a proposal from James while they were enjoying a romantic boat ride on Lake Como in Italy.
At the time, proud sis Paris wrote: "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!"
Nicky and James began dating in 2011 after meeting at Petra Ecclestone's wedding to James Stunt.
This will be Nicky's second marriage. She was previously wed to Todd Meister in 2004 but that union was annulled after just a few months.
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