Britney Spears tweeted that she had "one of the most magical nights of [her] life" last night in Vegas, and it's easy to see why. She was in one of the most exciting cities on the planet, got to eat as much chocolate and fancy cake as she possibly could, was surrounded by friends and family, AND had a big ol' diamond engagement ring on her finger!

Jason Trawick popped the question Thursday night, on his 40th birthday, with a stunning 3-carat Neil Lane sparkler. The ring has a large circular diamond in the center, with a diamond-paved band. Now it isn't Kim Kardashian big, but we sincerely hope Brit and her man's marriage lasts a lot longer than 72 days...
To celebrate, the couple jetted to Sin City for a joint birthday-engagement bash. They started off the evening with a fancy cake and celebration at the Hard Rock Hotel, and followed that with a feast at the Chocolate Lounge at the Sugar Factory in the Paris Hotel. Brit LOVES her sweets, you know. Apparently there was even a chocolate fountain of sorts and the dudes will all get celebratory chocolate cigars. Then, the party reportedly moved to the Chateau nightclub.
The singer tweeted before heading on their mini-vacation: "Still glowing! About to jump on a plane to Planet Hollywood in Vegas. Throwing a Bday Party for Jason at Chateau Night Club. So fun. Xxoo"
Afterward, she referred to Trawick, her former agent, as her "fiance" on Twitter and raved about the festivities. She wrote: "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"
Oh, and at some point during the night, she updated her Facebook relationship status to "Engaged." Forget Trawick's statement and Spears' rep's confirmation, an updated Facebook status is how you know it's legit. See more Britney Spears pics here and take a look at their relationship over the years: