They were Flower Power's oddest sweethearts, a gold-chained pip-squeak and a bare-bellied glamour-puss who made us believe that love sprang eternal from their spangled hearts. Starting with their top 10 single ''I Got You Babe'' (1965) and continuing through their weekly CBS hit, The Sonny and Cher Comedy Hour (1971-74), they were living proof that a groovy kind of love could really last. But on Feb. 20, 1974, after six years of marriage and more than 11 together, Cher sued for divorce on the grounds of involuntary servitude. The break registered an 8.0 on the pop-cult seismograph-for those who hadn't realized it yet, the '60s were finally and irrevocably over. Sonny may have expected the break, but the couples' fans were flabbergasted. They had no idea that for the past year, the two had been sharing their 54-room house in L.A. not only with their toddler daughter, Chastity, now 24, but with their various and respective lovers. In fact, the pair had reportedly tolerated each other's dalliances for years, but the gig didn't end until '74, when Cher moved in with record mogul David Geffen. Besides filing for divorce, Cher tried to get out of her contracts with Sonny, but the man who'd made her a star knew that his popularity rested on standing beside her, and he slapped her with a $24 million lawsuit. Ultimately, the pair resolved their legal differences before making another stab at a series in 1976. The duo that once personified marital bliss has since come to embody nasty divorce. While the two have reunited professionally on occasion-most recently to sing ''I Got You Babe'' on David Letterman's show in 1987-their get-togethers have apparently done nothing to diminish their animosity. Bono, 59, the former mayor of Palm Springs, Calif., who's now seeking a congressional office, scathed his ex in his 1991 tell-all, And the Beat Goes On. Complete with chapter titles like ''She Didn't Even Say Goodbye'' and ''I'm Too Big to Cry,'' the book includes a 1972 entry from Sonny's journal: ''Cher wants to run like a racehorse, but she can't find a track. I used to be the jockey, but Cher quite nicely shoved the saddle up my a -- .'' Cher, 47, who's turned infomercials into an art form, got her licks in last year, when she rerecorded ''I Got You Babe'' with America's newest odd couple, Beavis and Butt-head. When Butt-head riffs on Bono at the end of the song, asking, ''Isn't he a wuss?'' Cher responds with little hesitation, ''Yeah, well. Yeah.''
TIME CAPSULE Feb. 20, 1974 Heads turned over The Exorcist, while listeners grooved to Terry Jacks' ''Seasons in the Sun.'' Gore Vidal's novel Burr was No. 1 on the best-seller list, and All in the Family was winning the ratings war a third consecutive season.