On Dec. 18, the "Genie In a Bottle" singer strutted her stuff on TikTok to the sound of Megan's hit single "Body." She rocked a skintight bodysuit and a long, platinum blonde ponytail for the occasion.
The artist wrote in the caption, "40! #birthday #bodyodychallenge #bodychallenge."
Megan's song, which she first debuted at the American Music Awards in November, has gone viral on TikTok, with many users recording themselves doing Megan's dance moves Megan from her steamy, star-studded music video. (Blac Chyna and Taraji P. Henson make appearances!)
While XTina didn't try her hand at the choreography, she definitely made a sultry birthday video to remember. The Burlesque actress also posted the video on Instagram, where she received lots of birthday well wishes from fans.
"Thank you for being such a great role model at every age!" one fan wrote in the comments section. "You give confidence and keep fighting no matter what. Happy birthday!"
Another added, "Absolute LEGEND! Happy 40th my Queen!!"
A third declared, "HAPPY BIRTHDAY ICONIC GODDESS!!!! We love you!!!!"
On her Instagram Story, Christina reposted some of the birthday love she received this year from friends like Samantha Burkhart, Tiana Brown Gandelman and Teddy Coffey.
It's not just Christina's birthday that she's celebrating this month. The star also appeared on Late Night With Seth Meyers on Dec. 16 to perform "The Christmas Song," a classic holiday tune that she first covered in 1999.
She also honored the 20-year anniversary of her 2000 Christmas album My Kind of Christmas by posting a throwback video on Instagram.
There's a lot to celebrate in XTina's world this month, and let's hope there are more fun videos coming our way to mark every occasion!