Photo Credit: Jordan Strauss/WireImage
Oscar-winner Paquin, 27, became engaged to her True Blood costar Stephen Moyer, 40, in August 2009 (and don't forget, the passionate performers topped our iVillage Entertainment Awards poll last month for Most Sizzling Sex Scene!)
While Paquin's declaration may not be shocking news to Moyer, Radar Online reports that those who were in attendance at the taping of the public service announcement "had no idea she would be making the announcement."
Other stars involved in the public awareness campaign include Kim Kardashian, Cynthia Nixon, Wanda Sykes, and Elton John.
Are you surprised to hear Anna Paquin is bisexual? Chime in below!