Oh, the joys of live theater. The final preview performance of the Broadway revival of Bye Bye Birdie was halted for about 20 minutes Wednesday night when the electronically controlled set failed to clear during a scene change. The curtain fell on the big-budget musical, which is slated to open Thursday night, and star John Stamos appeared in front of a lights-up auditorium to stall for time as technicians worked backstage. Stamos called out to fellow celebs in the audience, including comedian Don Rickles, who shouted out from his seat to rib the former Full House star to get a haircut. “Are they gonna fix it or is this going to be a weekend?” Mr. Warmth added.

Then Stamos cajoled his Full House costar, Bob Saget, who was seated in the row behind Rickles, to come on stage and help him fill the time. Saget cracked a few jokes, speaking through the mic rigged to Stamos’ forehead. “I’m really glad your crotch is not miked.”

Stamos’ Bye Bye Birdie costar Gina Gershon also came out, asking the duo to keep vamping (at one point, she reappeared with an old poster of Stamos from his teen idol days). “I saw Full House for the first time a few weeks ago at the dentist’s,” Gershon said. “What was that about?” Saget replied: “Oh, it’s basically just like Brokeback Mountain — but as a sitcom.” Saget also asked Gershon: “Gina, do something from Showgirls.” (The actress obliged with a quick feathering of her hands in front of her face.) The rubber-bodied comic actor Bill Irwin, who plays the uptight father in Birdie, also emerged to perform a little clowning with the dropped curtain.

After a roughly 20-minute delay, the show resumed — appropriately enough, to the production number “Put on a Happy Face” — and ran through to the curtain call without further incident.

“Accidents happen,” Saget told EW after the show. “He’s my brother,” the comic said of Stamos. “I’d do anything for him. And he’s certainly always been there for me.” And noting that he had to clamber rather awkwardly onto the stage, Saget quipped, “I think I threw my knee out.”