Britney Spears is engaged to her long-time boyfriend Sam Asghari, in more happy news for the singer following a win in her protracted court case.

The pop superstar, who last week celebrated a legal victory in the conservatorship that controls her life and career, shared a video of herself wearing a diamond ring on Monday.

“I can’t f—ing believe it”, Spears wrote on Instagram, alongside diamond ring emojis and a love heart.

The clip featured an emotional-looking Spears, 39, showing off the ring while Iranian actor and fitness instructor Asghari, 27, asked if she was pleased with it.

“Yes!” Spears replied.

The couple met in 2016 after Asghari landed a role in one of Britney’s music videos and have been together ever since, but their first encounter was not perfect.

In 2018, Asghari told Men’s Health about their awkward first exchange on the set of the superstar’s Slumber Party music video.

“She said, ‘Hi, I’m Britney,’ and I said, ‘I’m sorry. What’s your name again?” he said.

“I tried to be funny. I don’t think anybody got it.”

Obviously the bad joke was no hurdle to the romance, with Asghari’s manager, Brandon Cohen, confirming their engagement in a statement to People magazine.

Mr Cohen said he is “proud to celebrate and confirm the engagement”.

“The couple made their long-standing relationship official today and are deeply touched by the support, dedication and love expressed to them,” Mr Cohen said.

Spears recently praised Asghari for supporting her during “both the hardest and best years” of her life.

In February, Asghari told People he had always wanted nothing but the best for his “better half”.

“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,” he said at the time.

The pair make workout videos together for social media and often post about their relationship.

 

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In June, Asghari told Entertainment Tonight he was “absolutely” hoping to propose to the Gimme More singer, adding his opinion that marriage is “the whole point of a relationship”.

The engagement news comes after Spears’ father Jamie petitioned a court in Los Angeles to consider terminating conservatorship after 13 years.

He said his daughter’s circumstances had changed “to such an extent that grounds for establishment of a conservatorship may no longer exist”.

In August, Mr Spears agreed to step down as Britney’s conservator, but her lawyer accused him of attempting to extort her because he was taking his time to do so.

The singer’s personal affairs and money have been controlled by a complex legal arrangement since 2008, after she suffered a series of public breakdowns.

Reports circulated that she had shaved her head, was partying almost constantly and had started speaking with a fake British accent.

The nature of Britney’s mental health issues have never been publicly revealed, but she was hospitalised for psychological assessments twice in that year and lost custody of her two children.

Spears has been demanding the conservatorship be brought to an end for months, and also accused her father in court of being abusive in his role overseeing her estate.

• Related: Britney soon to be free, here’s what you need to know

At a hearing in June, Spears alleged her conservators were preventing her from marrying Asghari and starting a family together.

She claimed they would not permit her to have a contraceptive device removed as they did not want her to have any more children.

Spears has two sons with ex-husband Kevin Federline, Sean Preston and Jayden James, who are 15 and 14 years old respectively.

She was reportedly granted 30 per cent unsupervised visitation rights in September 2019 and recently posted a photograph of the three of them together on Instagram.

“I’m extremely lucky because my two babies are such gentlemen and so kind that I must have done something right”, she wrote.

-with AAP