Gwyneth Paltrow's husband - Coldplay's Chris Martin - caused traffic chaos after crashing his car into the back of another driver.

The singer was driving through London's Belsize Park when he slammed into the back of an unnamed woman's Honda.

But the rocker refused to leave his BMW X5, staying put in the driver's seat as the other motorist talked to him through the window.

Martin's car suffered no damage while the other vehicle now sports a large dent in its rear bumper.

Meanwhile, Paltrow's mother Blythe Danner sparked rumors the couple are expecting their second child.

She let the secret slip in October when she told a reporter, "Yes, I am going to be a grandmother again. Well, I think so. Oh, well I have not checked lately."

The couple - who have an 18-month-old daughter Apple - have since refused to confirm or deny the claims. Martin told British magazine Heat, "I can't tell you about Gwyneth, you know that, she'd kill me."