Jude Law and Sienna Miller have reportedly engaged in a war of words, trading insulting messages back and forth between mutual friends.

A source told the Sunday Mirror that Jude told friends that Sienna was “dull, fake and boring” while she countered by calling him “fat, egotistical and juvenile.”

Jude was also less than complementary about Sienna’s new boyfriend Jamie Burke and she mocked his being linked to various Hollywood starlets, such as Lindsay Lohan and Natalie Portman.

A mutual friend of the pair told the newspaper: “After splitting up, Jude and Sienna said they would try to remain friends. But this simply hasn’t happened.”

“They are both angry and bitter. They just keep on trading vicious insults, and keep fighting back and forth.”