sit on (one's) tail

sit on (one's) tail

To follow close behind one, especially in a car. Why is this guy sitting on my tail when I'm already going over the speed limit? I sat on his tail for nearly 30 minutes before I finally had a chance to pass him.See also: on, sit, tail

sit on someone's tail

drive extremely close behind another vehicle, typically while waiting for a chance to overtake.See also: on, sit, tail