Britney Spears and Sam Asghari just proved they're going to be together "'Till the World Ends."
On Sunday, Sept. 12, the superstar announced that she got engaged to her longtime boyfriend after being together for five years. And in true Britney fashion, she shared the engagement news with a cheeky post on Instagram, writing, "I can't f--king believe it."
Alongside her message, the 39-year-old performer uploaded a video that captured her gorgeous round-cut engagement ring. In fact, the pop star's shiny sparkler is a four-carat diamond that was designed by Forever Diamonds NY.
The brand revealed all the dazzling details about Britney's one-of-a-kind jewelry piece in a press release shared with E! News on Sunday.
For one, no detail went unnoticed as Sam took months to find the perfect engagement ring, which is why he enlisted the help of Forever Diamonds NY to create a custom ring for his leading lady.
The Can You Keep a Secret? actor worked closely with Roman Malayev, Forever Diamonds NY Founder and Master Jeweler, to bring his vision to life.
Sam said in a statement, "Every designer I spoke with about the ring was amazing with great ideas, but I just clicked with Roman—we really connected on the design and he was as excited as I was to make it special—that's why I chose him."
The fitness trainer would end up falling in love with a four-carat round brilliant stone in a platinum cathedral setting.
According to the brand, Sam added an extra touch of elegance to the ring by including pavé detailing on the bridge and flush set diamonds on the prongs and basket.
Making the statement piece all the more special? The 27-year-old star engraved the word "Lioness," his personal nickname for Britney, inside of the band.
To honor the couple's engagement, Forever Diamonds NY sweetly named the design, "The Britney."
Of course, Sam's ring perfectly complemented his romantic proposal.
A source tells E! News, "Sam had it planned out that today would be the day he was going to propose to Britney. He had the ring and couldn't wait any longer."
"He proposed to Britney at her home with a solitaire diamond by Roman Malayev," adds the insider. "Britney was ecstatic. She's wanted this for a long time and her dream finally came true. They are celebrating at the house and enjoying this day together just the two of them."
Sam and Britney's relationship milestone comes exactly one week after a source close to the fitness guru told E! News he was more than ready to pop the big question.
"Engagement has always been in the cards for Sam and Britney, without question," the insider revealed at the time. "It's the direction their relationship has been heading for nearly two years now. It's always a discussion and it's not a question of if, it's when."
Relive the couple's fairytale romance here.