The basic pitch for "Swimfan" can be boiled down to three words: "Fatal Attraction, Jr." A high school-set obsessive romance, "Swimfan" shamelessly appropriates the plot of its infamous '80s forebear and reinvents it as the most mild of teenage titillation, a movie that somehow escaped its direct-to-video destiny apparently only to be an embarrassing wreck on a much larger screen.