For a lot of people, Casey Affleck finally admitting that Joaquin Phoenix had been playing a joke was just as surprising as a Lindsay Lohan relapse. But would you be shocked to know that David Letterman was supposedly in on it?

Although Affleck, the director of the “documentary” I’m Still There, recently claimed Letterman was unaware of Phoenix’s “terrific performance,” a Late Show writer tells an entirely different story.

In a newspaper interview printed last year, Bill Scheft claimed that Joaquin’s February 2009 appearance was all an act. “Think Andy Kaufman without shaving. That’s what he was doing. And Dave knew about it and Dave loved it because he could play along. He could do whatever he wanted with it. And he did, and it was great television. But I will take credit for the line, ‘I think I owe Farrah Fawcett an apology.’ That line was mine. I gave that to him during the break,” Scheft revealed.

“Dave loves that. He had a ball. He likes anything that’s good television, and he knew that’s good television,” Bill added. “I’ve told people that (everyone was in on the joke), and not only don’t people believe me, they tell me that I’m wrong and that (Phoenix) is a schizophrenic and he needs help and he’s going to end up like his brother. I said no. I saw the segment notes. It’s an act. I saw Ben Affleck’s brother taping the whole thing from offstage.”

So now that the jig is up—what will this mean for Phoenix’s upcoming reunion with Letterman? We’ll just have to tune in Wednesday to find out.