Lady Gaga is set to guest-star on the November 16^th episode of Gossip Girl, playing—guess who?—herself. B books the pop superstar to perform a private show, a ploy to regain her Queen B status after being dethroned. Gaga, an NYU alum in real life, will be performing her new single, “Bad Romance.” Here’s hoping bad romance for G will mean some good karma for B…