Britney Spears is engaged to her longtime partner Sam Asghari.

The 39-year-old posted the news on Instagram on Sunday night, flaunting her new ring, designed by New York City jeweller Roman Malayev.

"I can't f**king believe it!!!!!" Spears captioned the video of her and Asghari, where she sports a red-tipped manicure and kisses her new husband-to-be off-camera.

In a separate Instagram post, the 27-year-old shared a photo of him and the Circus hitmaker kissing behind a close-up of her newly blinged-out ring finger.

Asghari, who began dating the singer after meeting on the set of the Slumber Party music video in 2016, has been a strong defender of his pop star partner through this year, during which she has been fighting to leave her 13-year conservatorship. In a testimony in June, Spears alleged that the legal arrangement disallowed her from remarrying and having any more children. In a statement issued to People after the shocking allegations, he expressed his hope for the future.

"I have always wanted nothing but the best for my better half, and will continue to support her following her dreams and creating the future she wants and deserves," he explained. "I am thankful for all of the love and support she is receiving from her fans all over the world, and I am looking forward to a normal, amazing future together."

The news of the engagement comes a week after the star's father, Jamie Spears, announced he had filed a submission to urge the courts to release her from the conservatorship, citing that he no longer thought it was necessary.