Mischievous Joaquin Phoenix created huge professional problems for co-star Mira Sorvino on the set of new film 'Reservation Road' - by telling her agent the actress was hiring a new representative.
The practical joker spent the entire movie trying to trip Sorvino up in tense scenes and make her forget her lines, but it was his secret chat with the actress' agent that really landed her in trouble.
She says: "He told my agent when she came to the set that I had been meeting with other agents from CAA (Creative Artists Agency) and did she know.
"I was like, 'What? Tell her that you're lying.' She's standing there with this pleasant smile on her face and not sure if he's trying to bust me for real.
"He's always got that kind of cutting edge pranky humour, but he did lighten things up on set."