Mischa fell foul of Paris when she started dating Cisco Adler who was engaged to the heiress's pal Kimberly Stewart.
And when asked about Paris at a post-Baftas party, the actress didn't mince her words.
Mischa told the Mirror: "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 seems to hate everyone around her age who is more successful. Silly bitch."
The actress also mocked Paris's appearance at the Brit Awards.
"I tuned into the Brits because I like to know what's going on in British music and I saw her and I was like 'what?'
"She was coming out with all this ridiculous stuff like 'I love London because whatever'. Purleese."
ananova.com
Bookmarks