Kieran Culkin admits getting Mark Ruffalo high during play

Kieran Culkin has admitted to getting Mark Ruffalo high during a play.

The Succession star has revealed that he once got the Marvel star high during a 2000 Broadway performance of The Moment When when he was a teenager.

"I was 17 and stupid," Kieran, 42, confessed in a recent interview with The Guardian.

The A Real Pain star went on to explain that he had swapped a prop joint for one containing real marijuana.

"I'm like, 'I thought this was a good prank. I'm stupid. Oh my God, I'm so sorry.' But actually, they loved it," he recalled. "Mark says, 'I haven't smoked pot in 10 years. The second half's going to be so much fun.'"

The actor then revealed that the Poor Things star wasn't the only one who enjoyed the prank.

"There was this other actor who had never smoked pot in her life. She goes, 'Is this what being high is? This is lovely,'" he remembered. "And then Phyllis Newman comes in and goes, 'I haven't smoked pot since the 1960s. Thank you, darling.'"

However, Kieran then recalled that the stage manager was less than pleased.

"The stage manager comes stomping in and goes, 'I don't care whose it is, or what happened, but Kieran, give me the joint.' I sheepishly handed her the roach and she said, 'Ruin your life on your own time,'" he said. "I know, I know. But I was young. I'm 42 now. I know better. I'm not going to try to get anyone high on stage."

Mark previously told the story on The Graham Norton Show in 2012, however, he didn't identify the "very naughty young actor" who pranked him.

Recalling his moment of realisation, he said, "Why's that dude standing backstage laughing at me?' And the kid who put the joint on the prop table is standing there, (laughing). And I just went, 'Oh s**t.'"