Credit: Kevin Mazur/

It's been mere hours since Britney Spears accepted Jason Trawick's marriage proposal and the 30-year-old pop superstar can hardly contain her excitement.

"Still glowing!" she tweeted Friday after Us Weekly exclusively revealed that she and her former agent will soon tie the knot.

The couple plans to celebrate their engagement -- and Trawick's 40th birthday -- Friday evening at Planet Hollywood and Chateau nightclub in Las Vegas.

"About to jump on a plane to Planet Hollywood in Vegas. Throwing a Bday Party for Jason…So fun. Xxoo" Spears -- mom to sons Sean Preston, 6, and Jayden, 5 -- added Friday afternoon.

A source confirmed to Us Trawick popped the question on his actual birthday, Thursday, when he and the "I Wanna Go" singer shared a romantic dinner. Trawick later confirmed the engagement to Access Hollywood and said he and his bride-to-be are "over the moon."

"This is something they've both wanted for a long time," an insider tells Us. "It's a way to cement their family. They're both extremely happy and can't wait to become man and wife."