Fox's The Littlest Groom debuted to puny ratings last night, finishing third in its time slot with just 7.5 million viewers. The network fared better at 9 pm/ET with 16.1 million viewers tuning in for the penultimate episode of My Big Fat Obnoxious Fiance. Elsewhere, Diane Sawyer's sit-down with Mel Gibson on ABC's Primetime drew 17 million worshippers, and the finale of NBC's couples-themed Fear Factor scored a series-best 18.6 million viewers. For more on the Gibson interview, see below.