Las Vegas served as a memorable backdrop for some unforgettable "Hills" scenarios -- from Brody Jenner's 24th birthday bash complete with a Lauren Conrad kiss to an unwelcome Spencer Pratt surprising Heidi Montag during a Brent Bolthouse business trip. Fast forward nearly 10 years (we can't believe it either), Whitney Port descended upon Sin "City" for her very own momentous occasion: her bachelorette bash. And because the rest is ALWAYS unwritten, the weekend extravaganza featured a familiar face from Whit's MTV days.

"@devinlucien @brodyjenner @omnianightclub #itswhitneybitch," the SoCal native added along with the Instagram snapshot above from Omnia Nightclub (where Brody was DJing) at the Caesars Palace club. Seems like only yesterday these two were at Les Deux hearing shrieks of "You know what you did!"

But this nostalgic reunion isn't all that transpired at the designer's eventful mini-vacay in the Silver State: BRITNEY SPEARS brought the special gal on stage for a performance of "Piece of Me" and a whole lot more. Check out 14 photos from #ItsWhitneyBitch, captured by the future Mrs. Tim Rosenman and her squad:

Kicking off the festivities with some very important headgear

"Gangs all here!" -- and these ladies look ready to take on this "City"

Uh-oh, the main lady is missing from this selfie action

It's time to pop some special bubbly

Whit is "so fresh and so clean" -- and TGIF

This crew is READY

SUSHISUSHISUSHI

Making sure the lipstick game is strong

Taking the party to Omnia Nightclub...

...and spending some QT with none other than Brody!

Recovering...with some R&R

Whit and her entourage are ready for Britney (Bitch!)

"I will never ask for anything else ever again. OMG. I can't even believe this happened."

And when it's all said and done, it's important to hydrate by some statues.

Wish Whitney and Tim an early congrats on their upcoming nuptials in the comments!