It's the Christmas Eve every little girl dreams of: A guy roughly 680 times your age who rarely changes out of his pajamas gets down on one knee (if he's able) and pops the question. Hugh Hefner is hoping the third marriage is the charm, having proposed to 24-year-old girlfriend du jour Crystal Harris on Friday, reports Reuters. The 84-year-old made his announcement yesterday via Twitter: "When I gave Crystal the ring, she burst into tears. This is the happiest Christmas weekend in memory." (More Hugh Hefner stories.)