Kieran Culkin opened up about getting Mark Ruffalo, 57, high while they were in a play together by swapping a prop joint for real-life marijuana.

The actor responsible for getting Mark Ruffalo high on stage during an off-Broadway play reveals himself: Kieran Culkin cops to the prank, which he blames on being '17 and stupid.'

Kieran Culkin has confessed. The star of “A Real Pain” and “Succession” admitted that he once swapped a prop joint for one spiked with real marijuana when he was cast in a stage production alongside Mark Ruffalo in 2000.

Kieran Culkin admitted that he once tricked Mark Ruffalo and other co-stars into getting stoned during a live theatrical performance. “I was 17 and stupid,” Culkin said in a recent interview with The Guardian.

My friend Danny delivered the single greatest stage performance I ever witnessed in person. During a play in college, a few of us in the crew replaced his character’s delicious milk chocolate with bitter baker’s chocolate.

Kieran Culkin has confessed to a prank that left Mark Ruffalo and others high during an off-Broadway play in 2000. The actor swapped a fake joint with a real one, leading to an unexpected on-stage experience.