One more time, everybody: Ashton Kutcher is "Punk'd!" out. The MTV practical joke show is history. Just because he might have a slight credibility problem ...

"I've become the boy who cried wolf," Kutcher, 25, tells the Associated Press, confirming that his decision to conclude the show after two seasons is not another hoax.

"Let's put it this way," says Demi Moore's squeeze. "I'm getting ready to start shooting two movies, I'm still working on 'That '70s Show,' I'm producing two other shows for MTV and creating a one-hour drama pilot for FOX ... I don't have the time."

Not that "Punk'd!" -- whose tricks included helping Jessica Simpson convince Nick Lachey that her hillbilly relatives were coming to live with them -- will completely disappear.

As is now happening with most TV series, the first season of "Punk'd" is coming to DVD -- on Tuesday.

According to AP, the two-disc set includes previously unseen footage and extended scenes of pranks. One memorable target that appears on the DVD set: Justin Timberlake, who was punk'd into believing that the IRS was seizing his home and possessions.

"People were really skeptical about this show in its first season," Kutcher said. "What I always said was, 'You don't look like a fool, you look like a human being.' It's humanizing. It brings you back down to a relatable level."

And this from someone who clearly knows about relationships.