Jack Black hides his bad films "like a sexually transmitted disease". The 'Kung Fu Panda' actor admits he is not keen on promoting the work he is ashamed of.

He said: "You don't just do something to do it. When you do a good movie you feel good at promoting it. "When it's a bad movie you want to release it quietly. You try to keep it a secret like an STD." However, Jack is not embarrassed by 'Tenacious D in the Pick of Destiny' - a fictional film about his comedy rock band - despite it being a major flop at the box office. He said: "I really liked the 'Tenacious D' movie. I was proud of that one."

The 38-year-old star recently revealed he wants to lose weight so he can appear in more nude scenes. He said: "When I saw my rear end in my nude scene in 'Margot at the Wedding', it actually had a double chin. I've joined a gym because the next time you see me naked I'll be trim."