She's got a hot new single, but she's not single anymore. "American Idol" runner up Kimberley Locke broke her romantic news only to "Extra" about the marriage proposal that she made!

"If I had waited for him to ask me to marry him, it would have been a while, I'm sure," Locke admitted.

Kimberley is officially engaged to her high school sweetheart, Don Campbell, a barber who styled his way into Kimberley's heart 12 years ago. "He's a hard worker, and he's got a great heart," Locke told us.

But Don's heart nearly skipped a beat thanks to Kimberley and her mom's sweet proposal plan: "I said, 'Momma, here's the ring,'" Kimberley recalled. "She layered it on the plate and took the brownie and smooshed it. He bit into the ring, and he's totally freaked out. I rinsed it off and brought it back, and I got down on my knee and asked him to marry me."

The couple will say their "I do's" next year. Congratulations, Don and Kimberley!