It doesn't help that Lopez plays a lesbian or Affleck a dumb thug.
The movie is Krakatoa, the volcanic fallout immediate and far-reaching. This week, the couple - who say they were just friends during the Gigli shoot (Lopez was newly married to Cris Dancerguy) - vowed never to work together again, though they already have in Kevin Smith's Jersey Girl.
That film, shot here after the two became lovebirds, has been pushed back from November to February. Miramax announced the change in June, ostensibly to give Bennifer time to promote Gigli overseas. But the distributor probably hopes that audiences will contract repressed-memory syndrome.
Affleck has done his best work in art-house movies, Good Will Hunting and Chasing Amy, where the Sexiest Man Alive also chases a lesbian. Lopez succeeds in conventional romances, though her best performance is in Steve Soderbergh's Out of Sight, possibly the steamiest caper flick of the '90s.
Gigli's R rating will ward off Lopez's core audience of teenage girls. The movie's utter crassness, jabs at the mentally challenged, a thumb sawed off by a plastic knife, and brains that end up in an aquarium will ward off everyone else.
Oh, and it's not funny. Not even unintentionally.
There's such a thing as too much publicity - heightened expectations lead to a more punishing fall. Studio executives need only recall that trifecta of cinematic catastrophes, Heaven's Gate, Ishtar and Showgirls. The glory of the first Matrix was its unexpected thrill ride, while The Matrix Reloaded came up against a mighty fortress of hype. The Hulk might have fared better with less hulkish promotion.
But Gigli would have been horrible if it had been sneaked into theaters with unknowns. Good movies start with a strong script enhanced by insightful direction. This has neither. Filmmaker Martin Brest should have axed the screenwriter.
Oh, right. He's the screenwriter.
It's shocking that Affleck and Lopez, who stepped in after a wise Halle Berry declined, agreed to such dreck, more amazing that they fell in love after uttering such garbage.
It's possible they'll be luckier with Jersey Girl. Couples have done superb work - Bogart and Bacall, Tracy and Hepburn, Burton and Taylor. Conversely, there's Madonna: Madonna and Sean Penn in Shanghai Surprise, Madonna directed by Guy Ritchie in Swept Away.
And some singers - if you think that's what Lopez is - have fared just fine on screen. True, you have Paul Simon's One Trick Pony, Paul McCartney's Give My Regards to Broad Street, and Bob Dylan's Renaldo and Clara. But there are also the fine films of Frank Sinatra, Doris Day and Lena Horne.
Showgirls and Valley of the Dolls have, over time, become guilty pleasures, suitable for video junkfest festivals, especially if viewed as accidental comedies. Time is unlikely to help Gigli or Swept Away or the Mariah Carey clunker, Glitter.
Lopez is said to be devastated by the reviews. Why? She and Affleck found each other while being paid a reported $25 million.
Gigli won't do an iota of damage to either of them, only to fans too foolish not to stay away.
Contact staff writer Karen Heller at 215-854-2586 or kheller@phillynews.com.