Britney Spears took the plunge at Elton John's annual Oscars bash Sunday night, wearing a very daring Michael Costello gown that showed lots of cleavage.

The singer, who is currently in the middle of a residency at the Planet Hollywood Resort & Casino in Las Vegas, brought boyfriend David Lucado along. "Getting ready to go to Elton and David's party!" she tweeted with a photo of the couple. "Love this amazing event that's for a great cause."

The event reportedly raised over $5 million for Elton's AIDS Foundation, and was attended by the likes of Heidi Klum, The Kardashians, Aerosmith frontman Steven Tyler and Whoopi Goldberg, who was just one of several stars to hit the party after attending the Oscars.