Brian Austin Green and Sharna Burgess have been keeping a big secret: They’re engaged! The couple broke the news on their podcast, Oldish, on September 22, revealing how the Beverly Hills, 90210 alum, 50, popped the question to the former Dancing With the Stars pro, 38, back in July at his own surprise birthday party. “I was like, ‘That’s the perfect place to do it,’” said Brian. “[She] never saw it coming.”

While he and Sharna have yet to begin the wedding planning process, there is one thing the pair — who share 14-month-old son Zane and co-parent Brian’s four other children — are certain of, a source exclusively tells Life & Style. “On their big day,” says the insider, “Sharna and Brian want all of their boys to be involved.”

“Of course, I said yes,” gushed Sharna, who finally got to show off her ring on September 22 at the iHeartRadio Music Festival in Las Vegas.