Danny Glover has new competition when it comes to running with his “Lethal Weapon” partner Mel Gibson: Steve Martin. PEOPLE reports that the white-haired comedian and writer was in Chicago making his new movie “Novocaine” at the same time mighty Mel was in the Windy City making “What Women Want,” directed by Nancy Myers. Myers, says PEOPLE, happens to be a pal of Martin’s, having written his “Father of the Bride” movies. So the two schemed to put Martin in a scene in which Mel runs down the street and stops to look into costar Helen Hunt’s apartment. With the scene in the can, the rushes went back to the studio in Hollywood — where nobody seemed to notice that, out of nowhere, Steve Martin suddenly appeared in the scene. Finally, six weeks later, one exec piped up how funny it was to have Martin running with Gibson. That was the last laugh, however: The scene’s been cut from the picture.