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!

Common Names:

Name	Pronounced	Usage
Tye	TIE	English
Mikhailo	-	Ukrainian
Ruth (1)	ROOTH (English), ROOT (German)	English, German, Dutch, Swedish, Norwegian, Danish, Spanish, Biblical, Biblical Latin
Imam	-	Arabic
Delphine	['delfi:n]
Peni	-	Hawaiian