Britney Spears and Sam Asghari Are Engaged: Paris Hilton, Seth Rogen and More Congratulate the Couple!

Britney Spears and Sam Asghari are feeling the love from celebrity friends following their engagement!

The couple announced the news of the proposal on Sunday after more than four years of dating.

The pop star, 39, showed off her diamond ring on Instagram in a sweet video with Asghari by her side. "I can't f—ing believe it 💍💍💍💍💍💍❣️!!!!!!" she gushed.

The actor and fitness enthusiast, 27, also shared a close-up photo of the rock on his account as the two shared a kiss in the background.

Paris Hilton, who's engaged to Carter Reum, celebrated the news, commenting, "Congratulations love!! 😍 So happy for you! Welcome to the club! 👰🏼💍."

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Spears' former backup dancer Willie Gomez posted, " Awe you twoooo 🙌❤️‍🔥😍😍😍. CONGRATS GUYS!!!"

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Seth Rogen also shared well-wishes for the future husband and wife, writing, "Mazel!"

Britney Spears Instagram Sam Asghari and Britney Spears

Others who weighed in included Christian Siriano, who simply reacted with a series of fire emojis.

Asghari's manager, Brandon Cohen, shared in an additional statement to PEOPLE that 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," said Cohen, adding that Spears' new ring was designed by N.Y.C. jeweler Roman Malayev.

"He couldn't be happier to be involved and make this one-of-a-kind ring," Cohen added.

The couple was first romantically linked after meeting on the set of Spears' "Slumber Party" music video in 2016.

In August, she praised her now-fiancé on Instagram for helping her through the "hardest years" of her life.

"Not only has this cute asshole been with me through the hardest years of my life but he happens to be an extremely good cook 👨🏽‍🍳!" Spears wrote. "Fast & Furious franchise, don't miss out on your next star 🌟🏎️👗🤓 !!!!"

RELATED: Britney Spears Is 'Ecstatic' About Sam Asghari's Surprise At-Home Proposal, Says Source

In a March interview with Forbes, the Iranian-born actor opened up about the beginning of his relationship with Spears and admitted he was ready to take the next step in his career — and relationship.

"My priorities in life are to remain humble and understand where I came from and where I'm going," he said at the time. "I want to take my career to the next step when it comes to acting. I want to take my relationship to the next step, as well. I don't mind becoming a father. I want to be a young dad."

A few months later, the singer made it clear as she gave her testimony during a conservatorship hearing that she wanted to marry and have a child with Asghari — and a friend of the couple told PEOPLE that he was also ready to settle down.

"He's ready for marriage and kids with Britney and is serious about the relationship. She wants to take that next step and have that full life with him," said the friend. "As a couple they've hidden how they've really felt even from people close to them because they were anxious and scared, but now it's all out there."

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Following the explosive June court hearing, a source told PEOPLE that Asghari was the singer's "rock."

"Sam has been Britney's rock for years. He makes sure that she eats well and works out," the source said. "She leans on him for everything. He works and has his own life too, but is around as much as he can."