When Lydia Hearst quit her column at Page Six Magazine after the freelance writer who ghostwrote it included a comment dissing Hearst publications, her family’s company, it kind of seemed that the model/heiress didn’t have much of a sense of humor about the whole thing. Especially after “Page Six” outed her as a phony. But we were totally proven wrong last night when she turned up for her own Halloween party at 1Oak channeling Britney Spears’s 2003 Page SixSixSix costume. She even gnawed on a copy of the Post! It’s commentary — she’s biting the hand that fed her. What happens next, when she has a fashion video or a new sporty handbag that she needs “Page Six” to promote, well, that’s anyone’s guess.