Britney Spears Hits the Beach in Throwback Bikini Shot

Britney Spears is already missing her post-Vegas residency vacation.🌊🌊🌊 #tbtA post shared [...]

Britney Spears is already missing her post-Vegas residency vacation.

🌊🌊🌊 #tbt

A post shared by Britney Spears (@britneyspears) on

The pop superstar posted a throwback shot of herself in a bikini from her beach vacation. Spears has been laying low since ending her Las Vegas residency on New Year's Eve.

Spears recently ended a five-year residency at Las Vegas' Planet Hollywood and immediately embarked on a Hawaiian vacation with her sons, 11-year-old Preston and 12-year-old Jayden, along with her boyfriend.

Spears won't be gone from Las Vegas for long. According to Us Weekly, the singer signed a new deal to perform at the Monte Carlo resort's Park Theater starting in 2019.

Fellow pop star Lady Gaga is set to begin a 74-date stint at the Park in December. Bruno Mars, Ricky Martin and Cher also have recurring performances in the same theater.

Spears, who has 18.4 million followers, enjoyed some much-needed vacation time last week with sons Sean and Jayden in Hawaii after ending her Las Vegas residency on New Year's Eve.

With the end of her Vegas stint though, engagement rumors have also been heating up. Spears was seen wearing a big ring on her left finger in Hawaii this past week, leading fans to speculate that she and boyfriend Sam Asghardi are already engaged.

"[Britney] is really happy and I wouldn't be surprised if they got engaged," an insider told Entertainment Tonight on Friday. "Sam is really good with the boys and that makes Brit really happy. She cares a lot that the boys are comfortable with the person she's dating."

Asghardi, who met Spears when he was hired for her "Slumber Party" music video, is also "very understanding and flexible in regards to her work schedule, which is necessary," the source told ET.

Contributing: Daniel Levine