Lindsay Lohan has reportedly been involved in a fist fight after finding Brett Ratner in bed with a model.

The actress apparently turned up at the home of X Men: The Last Stand director Ratner's home only to find the man in bed with Romanian model Alina Puscau.

Even though Ratner is said to have given Lohan the key code to his front door, he failed to inform her that he actually had a significant other.

"Alina jumped out of bed and went ballistic,” a source said. “They started screaming at each other and took the fight first into the living room and then out to the driveway while Brett hid in the bedroom.”