A manifest abomination on every measurable level, "So Fine," the painfully threadbare comedy opening today at area theaters, is easily as transparent as the peekaboo jeans that give the film its nominal but squandered topicality. The film's only conceivable distinction is that it could be the worst that Ryan O'Neal has ever made, and that's saying something.

Anyone expecting an acid -- or just silly -- satire of America's current commercial erotic fixation, the bouncing and monogrammed derrie res that rum-dee-rum through jeanscommercials and pickup bars, has another think coming, and another movie. It takes writer-director Andrew Bergman forever even to introduce the gimmick, and gimmick is all it ever becomes.

O'Neal, stretching credibility tighter than the most distressed denim, plays an American literature professor at a stuffy little college. His father's garment business is taken over by a towering hood who inexplicably insists that the son be kidnaped from the campus and put to work on the bottom line, so to speak.

So, the son invents the jeans with the fanny windows in them to save the day, right? Wrong. As wrong as wrong can be. He meets the hood and his ratty wife, an alleged Italian bombshell for whom sonny boy develops an instant and patently preposterous infatuation. They must have each other; besides, the wife tells sonny, although her husband is seven feet tall, how you say, "the linguini just hang there." That's Bergman's notion of a knee-slapper.

The hero spends a night under the couple's bed, and, his clothes having been burned in the fireplace (don't ask), must don a pair of her jeans, slippers and a fuzzy pink top to get home. The jeans split, but not at the seam; instead two round holes open at each pocket. Then the world mistakes this for a daring, derriere-baring fashion innovation and a few million light years later the farce ends during a performance of the opera "Otello" back at il professore's college.

Throughout, the comedy is so labored and wan that the film almost becomes unfunny enough to be funny. Oddly, there's no contemporary resonance to it at all; Bergman has managed to take a topic with currency and devalue it into irrelevant imbecility. Even the film's spoof of a jeans commercial has no real satiric edge; it is not a knowing lampoon.

O'Neal's effete simpering act got tired long before "So Fine," and he offers no redeeming variations. His leading lady, to whom Bergman has given one of the least amusing come-on lines in screen history, is played by the scraggly and scrawny Mariangela Melato, veteran of a few Lina Wertmuller movies. Kicking and screaming with ineffectual frenzy, Melato looks, in her American screen debut, as if she had been dragged bodily out of context.

Jack Warden shows early possibilities as Jack Fine, the clothier-father; his face, indeed his whole head, is expanding into a David Levine caricature of itself. But when Bergman sends him into a steam room to plead with the gangster -- played by giant Richard ("Jaws") Kiel, one of the few actors with muscles in his forehead -- and he is enveloped in Ivory soapsuds, it's a portent of idiotic things to come.

Fred Gwynne has a moment or two as the dean, but former teacher Bergman's idea of jabbing at academia is as lame as his social commentary, which is to say, beneath the most sophomoric of sophomores. The film looks ugly and harsh, appropriately but not enjoyably. As a director, Bergman overelaborates to the point of exhaustion, but it can safely be said that he gave the script just about what it deserved, short of immolation immediately upon completion.