Kylie Jenner is getting in touch with her inner Christina Aguilera… again.

The 19-year-old reality star joined the pop singer for an early birthday bash (Aguilera turns 36 on Dec. 18), where she flawlessly channeled Xtina's 2002 "Dirrty" days -- specifically, the yellow-and-black bikini top and assless chaps worn by the singer during MTV's TRL Presents: Christina Stripped in New York City.

WATCH: Kylie Jenner Gets 'Dirrty' in Christina Aguilera Halloween Costume

Jenner documented the lavish celebration on Snapchat and Instagram, captioning one shot, "When XTINA wants u to dress as XTINA for her bday, you do it!!"

In her request, Aguilera was referencing the Keeping Up With the Kardashians star's epic Halloween costume from less than two months ago, inspired by Xtina's 2002 "Dirrty" music video.

WATCH: Kylie Jenner Recreates Christina Aguilera's 'Dirrty' Era Look and Dance Moves For Halloween

The birthday girl, clad in a multicolored fur coat, massive pink wig and sparkly party frames, loved Jenner's costume so much, she couldn't resist smooching her "Dirrty" doppelganger.

In true "bday behavior" fashion, party attendees danced to hits by Juvenile and Jay Z while noshing on an endless array of sweet treats including a three-tier cake complete with doughnuts, lollipops, gumdrops and ice cream.

The Kylie Lip Kit creator brought along two of her closest friends for the soiree, Jordyn Woods and Tiffany Sorya. Woods rocked a sequined mini and what looks like one of Jenner's famous pastel wigs, while Sorya tapped into her animal instincts with a leopard-print catsuit.

Towards the end of the night, Jenner and her pals exchanged their sky-high heels for more comfortable leopard-print pajamas and claw-foot slippers.

For more on Jenner's "Dirrty" looks, watch the video below.