Britney Spears partied until 4am to celebrate her engagement on Friday (16.12.11).
The 'Hold It Against Me' singer threw a joint engagement and 40th birthday party for her fiance Jason Trawick at the Chateau club in Las Vegas, spending money on Dom Perignon champagne and a chocolate fountain to adorn the room.
A source told the Daily Mirror newspaper: "Britney made sure there was plenty of Dom Perignon champagne flowing throughout the bash. She had a couple of glasses herself. She stayed until 4am when she and Jason returned to their 50th floor suite."
Writing on twitter, Britney said: "Tonight was one of the most magical nights of my life. Such an amazing time with my new fiance and our closest friends and family. Blessed. (sic)"
Meanwhile, Neil Lane, the designer responsible for designing the engagement ring Jason gave to Britney has revealed he has been creating the piece of jewellery - which features one main diamond and 90 smaller gems on an eternity band - for some time while she has been touring the world.
He told People: "Jason is a romantic and when I asked him to tell me about Britney and what The Ring would represent to them so I could find inspiration, his response was always the same - she is a princess.
"Texts came from all over the world, from Abu Dhabi to Mexico and I don't know where else."
Despite the ring being created when he was away, Jason was delighted with the final piece hen he went to pick it up from his store in Los Angeles.
Neil added: "Oh my god he loved it. The guy was so excited and nervous. At the end of the day, even with all the fame, he's still a normal guy who was about to propose to the woman he loves."