Britney Spears looks sexy in a series of new Instagram videos. Credit: Courtesy Britney Spears via Instagram

What is she up to? Britney Spears showed off her impressively toned bikini body on Monday, January 25, in a series of mysterious (and very sexy) dance videos that show her writhing around on the floor to Nathaniel Rateliff & the Night Sweats' "S.O.B."

The captionless videos, shot in black and white, show Spears, 34, dressed in a black bikini, stretching and sliding around on the floor before ruffling her hair through her fingers and throwing her arms up in the air.

The mom-of-two's figure is flawless, showing off abs as perfect as in her early "I'm a Slave 4 U" days.

But while the videos have got fans speculating as to the purpose of their existence, for now, the singing sensation is keeping quiet.

The "Perfume" singer is currently taking a month-and-a-half break from her Las Vegas residency show, Pieces of Me, and many fans speculated that the videos were likely a sneak peak at some new onstage routines.

But while the sexy new videos have definitely got the Internet talking, the singer was back to mom mode later in the day, when she shared a snap of herself taking her sons and one of their friends out for a chocolate milkshake.

Chocolate shakes are seriously the best! So satisfying.

A photo posted by Britney Spears (@britneyspears) on

Tell Us: What do you think Britney’s videos are all about?

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