Advertisements From the NY Daily News From 'Brady Bunch' to wild bunch Is nothing taboo in TV land? Christopher Knight and Barry Williams, who played clean-cut brothers Peter and Greg Brady on "The Brady Bunch," will portray gay lovers on "That '70s Show." Knight, 47, and Williams, 51, have already shot the episode, in which they move next door to Topher Grace's TV family, a Fox rep confirmed to us. Word is the former Brady siblings may even share a kiss. It would have been unthinkable in 1969, when the Bradys began their five-year run. Back then, you never saw Greg kiss any of the many girls he dated. The word "sex" wasn't mentioned until the series' final episode. Network censors wouldn't even let us see the family's toilet. We can just see the Bradys' housekeeper, Alice (Ann B. Davis), breaking up the boys' lip-lock with her broom. In real life, Williams has been married twice. Knight, who was the best man at one of those weddings, has also been wed twice. Knight's recent romance with "America's Next Top Model" Adrienne Curry, 23, was chronicled on VH1's "My Fair Brady." (In the new Playboy, she calls their sex life "elaborate" and "exhibitionist.") His TV fling with Williams is due to air in April.