Here's hoping the second time is the charm for Hugh Hefner and Crystal Harris: They're once again engaged and planning to wed on New Year's Eve, a Playboy source confirms to E!. Harris, 26, called off her first wedding to Hefner, 86, just five days in advance last year. But they got back together earlier this year and Harris moved back into the Playboy Mansion. She recently tweeted, "Dear past, thank you for all the lessons. Dear future, I'm ready." No word on whether Hef had to buy back her old engagement ring.