Jennifer Lopez had to calm her unruly 4-year-old twins, Max and Emme, backstage before her Friday night concert in Los Angeles, and did so without saying a word. A witness at the Staples Center event told us the kids were playing around on scooters backstage and were “speeding around the green room area and causing a ruckus, almost running over people and running into things.” Staffers were scurrying around trying to catch the twins and get them to chill out. While J.Lo is usually left alone right before she goes onstage, we’re told she was forced to come out of her dressing room and “gave Max and Emme that ‘mom’ look to reprimand them.” Our source added, “She got her kids off the scooters and back into their room.” A rep for Lopez told us: “Jennifer’s family has a private and secure area backstage at each show. Jennifer is a loving and responsible mom, she would never put her children or others in a dangerous situation.”