They mounted the small stage of the Beverly Hills Hotel Crystal Room yesterday, she smiling and pink-cheeked, he lean and tan. Flashbulbs popped like long strings of firecrackers for several minutes as they savored themselves and the moment.

Richard Burton and Elizabeth Taylor. Together Again. Announcing their roles in a restaging of the 1930 romantic comedy "Private Lives," which Noel Coward once told them, "I think I wrote for you."

Act Two: Paris. Amanda Prynne and Elyot Chase, divorced five years, have both remarried but stumbled across each other on their honeymoons. In a burst of passion, they abandon their new spouses and run away together.

Amanda: How long will it last, this ludicrous, overbearing love of ours?

Elyot: Who knows?

Amanda: Shall we always want to bicker and fight?

Elyot: No, that desire will fade, along with our passion.

Amanda: Oh dear, shall we like that?

Elyot: It all depends on how well we've played.

Someone asked if they feared their audiences would be distracted hearing such lines from the most famous bickering couple of our time, once married to each other, divorced, married to each other again, divorced, married to other people and now both separated again. "I don't think so," said Taylor. "I hope they find it amusing."

"There is a chance on a Saturday night you might have a rowdy audience that sees double entendres, but we're prepared for that," Burton said. " . . . The ironies of the situation were one of the attractions involved."

Zev Bufman, the producer who put the two together, flashed a huge grin at the clamoring crowd of 100 reporters as they scanned the press release calling the play "a 'natural' for the Taylor-Burton mystique." The two have not worked together on stage since Taylor did a silent walk-on as Helen of Troy in a 1966 Burton production of "Dr. Faustus" at Oxford University.

Bufman said the two would rehearse this fall, film a studio production for a later showing on Home Box Office, then break for Burton to complete another project before opening on Broadway May 5. Bufman said the pair would move to the Kennedy Center in Washington Aug. 10 and to Los Angeles Sept. 19. Directors for the play and the film and the rest of the cast would be selected soon, he added.

"I look forward to it enormously," said Taylor, appearing at the press conference in a black, purple, blue and orange caftan. "We've known each other for 20 years and we are still best friends."

"Are you still in love?" a reporter asked.

"Next question," said Burton. Taylor said, "This is a press conference on the play 'Private Lives,' not our own private lives."

Someone still wanted to know if they were struck by the similarities between their own history and the off-and-on romance of Amanda and Elyot. "We've already done that," Taylor said.

"Are you going to do it again?"

"I don't think so."

Amanda: I think very few people are completely normal really, deep down in their private lives. It all depends on a combination of circumstances. If all the various cosmic thingummys fuse at the same moment, and the right spark is struck, there's no knowing what one mightn't do. That was the trouble with Elyot and me, we were like two violent acids bubbling about in a nasty little matrimonial bottle.

Burton, troubled in recent years by a series of illnesses, looked and sounded healthy and said, "I'm almost back to normal." Taylor indicated the mishaps and health problems that had plagued her previous project with Bufman, "Little Foxes," would not recur. Burton is separated from his wife, Susan Hunt, and Taylor from her husband, Sen. John W. Warner (R-Va.). Under the hot lights, they did not hug or kiss, but they kidded and interrupted each other like very old friends. Taylor referred to Burton as "one of the finest actors . . .," prompting Burton to break in: "One of the finest?"

"Private Lives" has a number of physical scenes, including one enormous, furniture-destroying fight between the two principals. Burton said he and Taylor would give the play a different interpretation from the light comedic touch of Coward and Gertrude Lawrence, who played the principal roles (with Laurence Olivier as Amanda's new husband) in the original production.

When they were first married, Burton said, he told Taylor "we would become a middle-aged married couple and nobody would pay any attention to us." Surveying the banks of television cameras, he added, "well, it got worse . . . Elizabeth is a famous 50 years old and I'm 56, and we're still mystified that people are so interested in us."

Elyot: Come and kiss me darling, before your body rots, and worms pop in and out of your eye sockets.

Amanda: Elyot, worms don't pop.

Elyot kissing her : I don't mind what you do, see? You can paint yourself bright green all over, and dance naked in the Place Vendo me, and rush off madly with all the men in the world, and I shan't say a word, as long as you love me best.