Michael Bay has said directing Dwayne "The Rock" Johnson in Pain And Gain ruined his clothes because the actor was always covered in baby oil.
Michael revealed Dwayne Johnson's oily secret at CinemaCon in Las Vegas, reported E!
He said: "You have to keep a three-foot perimeter because he has a woman professional just lubing him up with baby oil.
"You get the stuff all over your outfit, you wreck your clothes."
Transformers producer Michael also told how Mark Wahlberg prepared for his role in Pain And Gain, a comedy due out in August about three bodybuilders who get caught up in a kidnapping and extortion ring that goes horribly wrong.
He said: "Mark could pound chicken very good. He ate nine meals a day, he gained 40 pounds, he's like a machine.
"He told me, 'Week two is going to be my peak so get all your beauty shots week two, week three, 'cause then I got to lose 40 pounds and go on a Denzel movie next.'"
Mark also stars in 2 Guns with Denzel Washington.