Timothee Chalamet refused a butt double for Marty Supreme.

The 30-year-old actor plays a ping pong star in the new sports drama and one memorable scene sees his character being spanked by Kevin O'Leary's pen entrepreneur Milton Rockwell.

Kevin told Variety: "When it came time to whack him, there was a stunt a**. There was a double. [Chalamet] wouldn't do it. He said he'll do it himself. He didn't want some other a** immortalized."

Kevin added that shooting "went on for hours," with director Josh Safdie doing about 40 takes until 4 in the morning.

Kevin also had to use a real paddle after the fake one broke on the first hit.

He said: "Josh was saying, 'You've got to wind up harder'. I was really whacking him."

Rockwell humiliates Marty by spanking him in front of his dinner party guests, in retaliation for Marty's entanglement with his wife, retired actress Kay Stone (Gwyneth Paltrow).

Kevin called it "a pivotal scene of humiliation" for Marty, because "he had p***** me off so much and insulted me so many times that capital punishment was correct".

He went on: "I never felt satisfied that he suffered enough for what he did. Even now, I'm still p*****."

Paltrow previously revealed her character has "a lot of sex" with the Dune star in Marty Supreme.

She told Vanity Fair magazine: "I mean, we have a lot of sex in this movie. There's a lot - a lot."

When asked if she's in a lot of "vulnerable positions" with the 'Dune' star, she replied: "Beyond".

Gwyneth added of Marty Supreme: "[I play] this woman who is married to someone who is in the Ping-Pong mafia, as it were ... They [the two characters] meet and she's had a pretty tough life, and I think he breathes life back into her, but it's kind of transactional for them both."

She went on to explain it was a new experience using an intimacy coordinator on set for the spicy scenes, adding: "There's now something called an intimacy coordinator, which I did not know existed ... I was like: 'Girl, I'm from the era where you get naked, you get in bed, the camera's on'."