BACKSTREET BOY AJ McLEAN POPS THE QUESTION TO HIS ROCKER CHICK ON STAGE!

A.J. McLean had a birthday to remember this year.
To cap off celebrating his 32nd birthday in Las Vegas Friday night, the Backstreet Boys proposed to his girlfriend Rochelle Deanna Karidis while on stage at the Hard Rock Hotel's Wasted Space nightclub, People.com reports.

"He got up on stage and the DJ turned the music off," an onlooker said. "He asked her to come up on stage and he got down on his knee and she squatted down with him. He asked her and she said yes and hugged him."

While on bended knee, McLean presented his bride-to-be with an engagement ring he purchased hours before at the Hard Rock Hotel's jewelry store, Rocks, a source told the Daily News. Though the singer had originally planned on buying a bracelet for Karidis, he opted for a larger upgrade instead.

"She seemed very surprised and didn't seem to know why he was getting on stage," the witness told People. "Even his friends were shocked. They all knew he was going to propose but didn't think he would do it tonight."