This 1991 feature is not for diabetics or connoisseurs of real people, but everyone else should have a ball. A well-to-do teenager (Ethan Randall) and his precocious kid sister (Thora Birch) gleefully lie, cheat, pull a sadistic prank on a moral inferior (Kevin Nealon), and sacrifice their pets in order to bring their estranged parents (Harley Jane Kozak and Jamey Sheridan) back together for Christmas. In smaller roles, Lauren Bacall, Leslie Nielsen (as Santa Claus), Andrea Martin (as a pregnant Armenian), and multiple plugs for Ben & Jerry’s ice cream are enlisted to bring some much-needed class to the proceedings, and Robert Lieberman directs it all with a straight face. G, 92 min. (JR)