Travis BarkerandKourtney Kardashianhave found their “forever.”

After nearly a year of dating, the Blink-182 drummer, 45, and the reality star, 42,got engagedon Oct. 17 at the beachfront Rosewood Miramar resort in Montecito, Calif. — and a family source tells PEOPLE in this week’s issue, on newsstands Friday, that it was a long time coming.

“The question was neverifthey would get engaged, it was more likewhen,” says the source. “Travis just adores Kourtney. He treats her like a princess and is a great guy.”

At sunset Barker led Kardashian down to aheart-shaped red rose arrangementon the beach, where he popped the question with anoval-shaped diamond ringhe designed with celebrity jeweler Lorraine Schwartz.

For more onKourtney Kardashianand Travis Barker’s engagement and other top stories, listen below toour daily podcast PEOPLE Every Day.

“Travis was nervous, but Kourtney didn’t hesitate for a second before she said yes,” says the source. Adds an onlooker: “Kourtney did not stop smiling.”

While the source says the proposal was a “complete surprise” for Kardashian, Barker had clued her family in on his plans.

“Everyone was great at keeping it secret,” says the source, who adds that the celebration wasfilmed for the Kardashians' upcoming Hulu show. “Kourtney’s family loves Travis.”

“It was a beautiful celebration,” says the source. “Everyone is very happy for them.”

Travis Barker and Kourtney Kardashian.Getty

travis barker and kourtney kardashian

Longtime friends, Kardashian and Barker first became romantic a year ago. Since going public in February, they’ve documented their travels around the world on social media as Kardashianhelped Barker overcome his fear of flyingafter he survived a deadly 2008 plane crash.

“Travis gives Kourtney a lot of credit,” says the source. “Kourtney feels this is such a special relationship. She feels appreciated.”

This will be thefirst marriagefor Kardashian, who has three children — Mason, 11, Penelope, 9, and Reign, 6 — with exScott Disickand has never been previously engaged. It will be the third for Barker, who was married to Melissa Kennedy from 2001 to 2002 and Moakler from 2004 to 2008.

travis barker and kourtney kardashian

Still, her kids will remain “her priority,” the source adds. “They are the most special to her.”

For all the details on Travis Barker andKourtney Kardashian’s romantic engagement, pick up the latest issue ofPEOPLE, on newsstands everywhere Friday.

source: people.com