Mischa Barton has taken a swipe at Paris Hilton - branding her a "silly b***h".'The O.C.' star says she's tired of the hotel heiress criticising other successful girls, but insists she isn't trying to compete with the blonde.She stormed: "Paris isn't my rival. I met her one or two times and she's making out there's this big rivalry between us and there so isn't."She added: "She seems to hate everyone around her age who is more successful. Silly b***h."Mischa - who angered Paris when she started romancing Cisco Adler, the ex of Paris' friend Kimberly Stewart - also slammed the party girl for pretending she doesn't steal men.She is quoted by Britain's Daily Mirror newspaper as saying: "She does steal other people's boyfriends!"Earlier this month, Paris' sister Nicky allegedly lashed out at Mischa when she spotted her at a party at the swanky Regent Beverly Wiltshire, in Los Angeles.
According to reports, Nicky snapped: "What is that fat pig doing here?", as the sexy actress arrived.