be (sitting) on (one's) tail(redirected from be sitting on his tail)
be (sitting) on (one's) tail
To follow close behind someone or something. Why is this guy sitting on my tail when I'm already going over the speed limit? The cops are definitely on our tail now—we have to turn ourselves in!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.