Kylie also revealed more of her Christmas celebrations, including her matching custom designer gown with daughter Stormi

KYLIE Jenner has accidentally exposed her slimmer-than-ever behind in leggings while dancing with her sister.

The 26-year-old makeup mogul performed cheerleading moves with her older sibling Kendall, 28, in a video posted on social media.

5Kylie Jenner accidentally exposed her slimmer-than-ever behind in leggings while dancing with her sister KendallCredit: Instagram/Kyliejenner

The pair enjoyed Christmas together with their other sistersCredit: Instagram/Kyliejenner

Kylie posted several Instagram Stories with Kendall as the duo celebrated Christmas.

The pair were seen making cookies together before Kylie posted an amusing video of them attempting old cheerleading moves from when they were at school together.

Kylie placed the camera at a low angle before she walked over to her sister who stood in a doorway in Kylie’s lavish Los Angeles mansion.

The Kardashians star was dressed casually in a pair of skin-tight black leggings that clung to her slim frame.

Kylie displays shrinking waist in matching gold gown with daughter Stormi

She paired the look with long white socks and a check fleece which she tied at the waist.

Kylie’s shrinking butt was in full frame as she lunged behind Kendall to help her get up into a cheer move.

Kendall dressed similarly casually in green yoga pants paired with a tight matching top.

Kylie said to Kendall: “We should do old-school cheer moves.”

She then counted her sister down before attempting to throw her up in the air.

SLIM SISTER

This was not the first time Kylie showed off her slimming frame on social media after supposedly losing some weight.

Kylie posed in her Christmas outfits along with her daughter Stormi, six.

The mother-daughter duo both wore matching custom Dolce and Gabbana gold dresses.

Kylie dazzled in her sequined dress which featured an off-the-shoulder neckline and long sleeves.

Stormi’s gold dress had puff sleeves and a full pleated skirt and she accessorized with a matching gold bag.

Kylie filmed herself and Stormi in a huge mirror after they finished getting ready for the night’s festive celebrations.

Kylie squealed, “Got my shoes on!” before panning the camera to Stormi.

Kylie showed off her shrinking buttCredit: Instagram/kyliejenner

5The model matched with her daughter, Stormi, for the Kardashians Christmas partyCredit: Instagram/kyliejenner

5The star is said to have lost weight recentlyCredit: Instagram/Khy