What did the Easter bunny bring Buffy the Vampire Slayer star Sarah Michelle Gellar? Some chocolate candies, one of those yummy cream-filled eggs and... a diamond ring! The actress and her matinee idol beau, Freddie Prinze Jr., announced their engagement over the recent Easter weekend at a joint birthday party for Gellar and her ICM agent, Eddie Yablans, Access Hollywood reports. The gem is reportedly from jeweler Cathy Waterman, who has designed pieces for stars such as Gwyneth Paltrow, Meryl Streep and Meg Ryan. Gellar and Prinze — who co-star in the upcoming live action Scooby-Doo film — have been dating for a year and a half.