After a whirlwind romance and ample PDA, Travis Barker finally popped the question to his girlfriend Kourtney Kardashian with a stunning oval-cut diamond ring. Loraine Schwartz, who happens to be the Kardashian-Jenner family’s longtime jeweler, has revealed all the details about how Barker worked closely with her during the making of the engagement ring.

"It's a flawless, beautifully cut diamond stone,” Schwartz exclusively told PEOPLE. "I worked on it with Travis and he was a really big part of it. He was really hands-on in the whole making of it. It's gorgeous and they're happy," she said.

Talking about their engagement, a source told ET that the pair is beyond happy about taking this next step in their relationship.

"Kourtney and Travis are over the moon. Getting engaged was always their natural next step and they are so thrilled. The proposal was gorgeous and romantic, and everything Kourtney wanted," the source said.

The source further said, "Their families are beyond happy and excited for them too. Their kids are very much looking forward to being an official big happy family, Kourtney and Travis really feel like they've found their perfect partner and match. They can't wait for this next step in their journey as a couple and to spend the rest of their lives together."

Barker proposed to his lady love on a beach in Montecito, California. It happened inside a beautiful heart-shaped circle of red roses and candles during sunset. Later that day, the newly engaged couple celebrated their happy moment with an intimate family dinner. Kim Kardashian celebrated her sister’s engagement with a sweet Instagram post of the couple kissing each other as Kourtney flaunted her new rock.

"KRAVIS FOREVER," Kim captioned the video along with the diamond emoji.

Both Kourtney and Barker took to Instagram to announce their engagement with a beautiful picture of them surrounded by roses on a beach which they simply captioned as “Forever.”

Besides Kourtney’s engagement, Schwartz also designed her younger sister Kim’s engagement rings from ex-husbands Kris Humphries and Kanye West.

Schwartz is behind some of Hollywood’s most memorable jewelry moments, like Blake Lively’s custom halo with over 100-carats of champagne diamonds, which she wore at the 2018 Met Gala, and Angelina Jolie's 115-carat emerald drop earrings, which she wore at the 2009 Oscars. She is also the brains behind Beyoncé's $5-million engagement ring from husband Jay-Z.

Travis Barker Travis Barker, pictured here performing at the Bellagio on Aug. 18, 2015, in Las Vegas, said to expect a new Blink-182 album this summer. Photo: Getty Images