Vesle Fenstermaker's inverted Miracle on 34th Street finds Carter Morrison stuffed--by his mother's Speedy Tuna casseroles and red jello parfaits--to fit the department-store Santa suit he's wearing during the holiday season in order to buy her a color tube. ""Carterdear's"" Mama, a sweet thing, lives on the realities of the soap operas she watches all day; but she's happier than most of the youngsters who line up to tell him all they want for Christmas--or his girl of the moment, a sick chick--or Carter himself, who's harassed by horrible phone calls from Big Rosalie (his ex-wife) and visits to Little Rosalie, his five-year-old who is too awfully much like her mother. All she wants is a little obscenity called Dolly Alive (who ""pee pees and poo poos"") which he finally buys for her and then trashes. The season builds, inevitably, toward that night before when he'll deliver the television set. . . but it disappears, since this metaphor of the modern world deals in games and roles and illusions all taken down to the selvage of that red ribbon--""Believe a little if you have to but not much. Toughen up, it's another hustle."" Santa-Baby may not be just the book you asked for; certainly it's one of those unexpected small pleasures with its sad, funny, unstorebought talent but it will sneak right up on you. A disconcerting and most appealing first novel for those who prefer Woody Allen to Bing Crosby.