The cast of “The Big Bang Theory” was asked Wednesday on one of their most famous scenes – cavorting in a big ball pit last season in an episode called “The Einstein Approximation.”

“That was a blast,” Jim Parsons said.

His co-star Johnny Galecki corrected him. “Once they cleaned the balls, it was fun.” Because, he explained, “they were filthy.”

“That was the dirtiest thing I’ve ever done as an actor,” Parsons says.


Kaley Cuoco says she remembers Parsons coming in for the next scene. “He’s looking at me and I’m like, ‘Have you showered today?’ It was like a film of black across his face.”

“It was awful,” Parsons says. “I washed my hands, and the sink was 
black water. Then I wiped my clean hands on a
 towel, and it would be damp, and I brushed it over
 my face, and there would be this swath of pink and
 gray.

“It was good for my hair, though,” Parsons says. “I
 realized that I need a drier product. I don’t
 need to use a gel or something.”

“And we had disinfectant spray for 
one another,” Galecki says.

For the producers, the problem was to fill the ball pit.

“I think we emptied every bin at
 every Chuck E. Cheese’s in Los Angeles,” creator Chuck Lorre says.

They could have caught the giant plaything at the end of an era, though.

“Ball pits are kind of on the way out,” says executive producer Bill Prady.
 ”They don’t really make them anymore. And we’re 
looking at the set, and we kept saying ‘More balls!’ “

“They said this is all the balls in
 Southern California. At one point they said we
have a truck coming down from San Francisco, but
we don’t know if it will be here in time.”

The ball pits are disappearing,  “Because it’s a sanitary issue,
right?” Galecki asks.

“Yeah,” says Purdy.

“And it should be,” Parsons says.