You can swill beer or ogle naked women at Sundance, but you can’t do both simultaneously. At a sold-out screening this week of the Lake Bell–Kate Bosworth thriller, “Black Rock,” Egyptian Theater guests were forced to chug beers in the lobby before watching the film. “A draconian Utah law prevents patrons from mixing alcohol with nudity, be it in the flesh or onscreen,” said a movie maven who was told “bottoms up” by an usher before watching the film that features “a much-talked-about nude scene with Bell and Katie Aselton.” A Utah Department of Alcoholic Beverage Control rep told us, “There were two options: pre-screen the films, or confine the area where alcohol is served . . . to a location where the films are not viewed (i.e. the lobby).” Patrons practiced their chugging skills, and the movie sold to LD Distribution for a reported $1 million. The seller, hip New York banner Submarine, has been Sundance’s hottest, selling eight other movies and unveiling a Spike TV development pact.