HAIRSPRAY star Nikki Blonsky played a prank on her father during a recent radio interview - when she convinced him she'd be baring all in her next film. The portly actress was appearing on New York's Z100 when DJ Elvis Duran persuaded her to play a practical joke on her dad. Blonsky then called her father, Carl, and broke the news that she had been offered the chance to follow up Hairspray with a porn film. As her dad begged her to reconsider, Blonsky said, "At the end of the day, isn't it my body? I'm 18." Eventually the actress confessed she was joking after her dad's protests had aired on radio. Relieved Carl said, "I just had a heart attack."