NBC's Just Shoot Me is a long shot for renewal, but it's certainly going out with a bang. The sitcom will air twofers on Tuesdays during sweeps, leading to a three-episode finale on May 20. ''It's like carpet bombing,'' jokes executive producer John Peaslee. In fact, bombshells will surround David Spade's eternally horny Dennis Finch: Guests include Gina Gershon, Jenny McCarthy, and Kristy Swanson -- Spade's real ex-girlfriend. ''There's a line where Kristy was supposed to say, 'Omigod, I forgot how cute Finch was,''' explains executive producer Judd Pillot. ''In front of the audience, she said, 'Omigod, I forgot how cute David was.''' Emotions ran high during taping of the last episode, in which Blush publisher Jack Gallo (George Segal) retires and turns the fashion magazine over to his daughter Maya (Laura San Giacomo). ''Everybody was crying,'' says Peaslee. ''You don't expect to see David Spade crying.'' Guess after seven seasons, it's hard to say buh-bye.