Naughty Harry Potter actress Miriam Margolyes has developed a saucy habit of flashing co-workers on film sets, because she's convinced it's the only way to cheer up grumpy stars.
The 69 year old admits she showed her bare bottom to Warren Beatty while they were working together on 1981 movie Reds in a bid to make him crack a smile.
She tells U.K. talk show host Graham Norton, "He is grumpy. He really is. So I mooned at him."
Margolyes also reveals she stripped off in front of director Martin Scorsese on the set of The Age of Innocence, adding, "I didn't moon him, I did these instead (my breasts).
"It was a long day and we'd done the costume parade at the beginning (of the film). (Everyone was) feeling tired and a bit listless, so I just flung off my brassiere."
But the actress was banned from bringing her naughty antics to the set of the Harry Potter movies, and instead her colleagues set up a 'swear box' which she had to contribute to every time she cursed in front of her young co-stars.
She adds, "You have to be very careful with children and they made a rule that I had to give a penny or maybe a pound to the World Wildlife Fund if I swore and, really, they did very well."