The 27-year-old actor proposed to Britney with a stunning ring designed by Roman Malayev at Forever Diamonds NY, ET has learned.
Sam spent months finding the perfect designer for Britney's custom ring, which is very personal to their relationship. The 4-carat round brilliant stone is set in a platinum cathedral setting. Sam enhanced the timeless, floating solitaire design with pavé detailing on the bridge and flush set diamonds on the prongs and basket -- but the sweetest detail is the engraving included on the inside of the band. That's where the word "Lioness," Sam's nickname for Britney, sits.
"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," Sam said in a statement. "That’s why I chose him."
ET spoke with Roman and his wife, Simone, at Forever Diamonds about the special ring and the vision Sam had for the piece of jewelry that really spoke to who Britney is to him.
"Sam wanted a ring that was timeless and elegant. He wanted something that was really worthy of her finger. And I think starting off with the classics was ideal. So we took a cathedral setting, we put four flush set diamonds into the basket, as well as four flush set diamonds into each prong," Roman explained. There is hidden accents of diamonds on the bridge itself. There's even a diamond that's hidden underneath, so when she takes it off, she'll have something to kind of like look at. And he even wanted to go a little bit above and beyond and engrave it with what he calls her, his own lioness. And that really is a true expression of who she is as a woman."
The lioness, Roman and Simone said, represents Britney's strength and beauty.
"He wanted to include the inscription, 'lioness,' because it really is a true representation of who she is. A fierce woman who's...," Roman said. "Strong," Simone added. "Admirable, beautiful."
While the jewelry designers didn't get to meet Britney during the design process, they felt like they captured her essence through Sam, who they say adores the pop star.
"The love of his life. His everything, his soulmate, his queen, his everything, I mean, what we got from this, is that they really are in love and soulmates," Simone said of Sam's love for Britney.
Roman continued, "He adores her, I think that's really the most important thing, is that you find somebody that you can connect with, that you wanna share the rest of your life. It's beautiful, it's just a beautiful time in their lives and we're just really thankful to be a part of it."
Fans and happy couples can be a part of it too, with the piece joining the Forever Diamonds collection as "The Britney Ring."
Sam and Britney announced their engagement on Sunday, after roughly five years of dating. The pair first met in October 2016, on the set of her "Slumber Party" music video.
"I can’t f**king believe it 💍💍💍💍💍💍❣️!!!!!!" Britney captioned the post, as fans shared their well wishes for the couple in the comments.
Britney shared another post Monday in honor of their engagement, calling the moment, "worth the wait."
"Words can’t even say how shocked I am 💍 … geez although the a**hole was way overdue 😜 !!!! It was definitely worth the wait …. yes world … that beautiful f**king man in that picture is MINE 😍 !!! I’m so blessed it’s insane 🌹🌹🌹 !!!!," Britney captioned the photo of her husband-to-be.
Sam's manager, Brandon Cohen, told ET that Sam and Britney are "deeply touched by the support, dedication and love expressed to them."
Sam has been Britney's biggest ally amid her recent conservatorship hearings, showing his support for his "lioness" on social media. Britney recently praised Sam for being with her "through both the hardest and the best years of my life."
The pair's relationship also played a significant role in Britney's explosive courtroom testimony earlier this year, when Britney claimed that, under her conservatorship, she is unable to get married or have another baby.
"Britney and Sam basically live their life as a couple under curfew. She wants to be free of all the restrictions and she is ready to fight for her life because that is what this is," a source previously told ET. "Sam feels so proud of Britney for finally having this moment. It's her liberation and it's a long time coming."
"Absolutely," he responded when asked whether he saw marriage in his future with the singer. "This is something that every couple should do. That's the whole point of a relationship -- we are a family.”