First Pix: Britney & Jason Celebrate!

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First Pix: Britney & Jason Celebrate!

It's official! Britney Spears and her new fiance Jason Trawick celebrated their engagement at Planet Hollywood Resort & Casino in Las Vegas Friday night, and we have the first pix of the happy couple!

The singer tweeted, "Tonight was one of the most magical nights of my life. Such an amazing time with my new fiancé and our closest friends and family. #Blessed"

MORE: Britney Spears Engaged 

During the romantic getaway, the couple also celebrated at Sugar Factory American Brasserie and Chateau Nightclub & Gardens at Paris Las Vegas.

Britney and Jason, her former agent, have been an item since 2009, and he reportedly popped the question with a Neil Lane ring Thursday, his 40th birthday, during a romantic private dinner.

"She's really happy," a source tells ET. "It's going to be a great weekend."

According to People, celebrity jeweler Neil Lane designed the engagement ring with a princess theme in mind. A round white diamond sits in a handmade platinum setting with 90 small diamonds around the eternity band.

Stay tuned to ET for more Britney news!