An early Christmas gift for Proposition 8 opponents, writer-director Steven Antin’s indifferently constructed, lazily written backstage musical is still worth checking out if you’re a guilty-pleasure enthusiast. Christina Aguilera (not terrible) plays a small-town waitress who, after hopping a bus to Los Angeles, gets a job as an all-singing, all-dancing showgirl at an upscale gentlemen’s club. Since the, er, eclectic cast also includes Cher -- although you’ll be forgiven if you mistake her for a West Hollywood Cher impersonator -- as co-owner of the Burlesque Lounge, Alan Cumming (camping it up as the MC), and an indispensable Stanley Tucci (the club’s been-there, seen-it-all stage manager), there’s serious, albeit disreputable fun to be had. The Bob Fosse-Goes-MTV musical numbers are a mixed bag, but Cher’s balls-to-the-wall torch ballad “You Haven’t Seen the Last of Me” neatly sums up the film’s gay, gaudy spirit. While there may be plenty of better movies released this holiday season, Burlesque is the only one you can take both grandma and your tranny BFF to.